Frequency domain channel state information (CSI) compression

ABSTRACT

An approach is described that includes receiving a CSI report, where the CSI report includes a channel quality indicator (CQI), a rank indicator (RI), and a precoding matrix indicator (PMI). The approach further includes constructing a precoding matrix based on a linear combination of a plurality of mutually orthogonal digital Fourier transformation (DFT) spatial beams, and determining a number of bits for the PMI of the precoding matrix. The approach also includes determining a space frequency matrix based, at least in part, on the number of bits for the PMI and the precoding matrix, and compressing the space frequency matrix. Finally, the approach includes determining a compressed PMI based, at least in part, on the space frequency matrix.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/417,302, having a 371(c) date of Jun. 22, 2021, which is a U.S.National Phase of International Application No. PCT/US2020/014235, filedJan. 18, 2020, which claims the benefit of U.S. Provisional ApplicationNo. 62/794,220, filed on Jan. 18, 2019, all of which are herebyincorporated by reference in their entireties.

FIELD

Various embodiments generally may relate to the field of wirelesscommunications.

BACKGROUND

In modern wireless communication systems, it is important to be able toestimate the characteristics of the channel between a user equipment(UE) and a base station. In order to accurately estimate the channelcharacteristics, the UE may report information concerning the channelcharacteristics (channel state information (CSI) to the base station.With this channel state information, the base station may selectappropriate communication parameters to more effectively undertake withthe UE. It is desirable to provide accurate channel state informationwhile minimizing the overhead to do so.

SUMMARY

An embodiment is described that is an apparatus that includes a memoryand at least one processor. The at least one processor is configured toreceive a CSI report, where the CSI report includes a channel qualityindicator (CQI), a rank indicator (RI), and a precoding matrix indicator(PMI). The at least one processor is further configured to construct aprecoding matrix based on a linear combination of a plurality ofmutually orthogonal digital Fourier transformation (DFT) spatial beams,and to determine a number of bits for the PMI of the precoding matrix.The at least one processor is also configured to determine a spacefrequency matrix based, at least in part, on the number of bits for thePMI and the precoding matrix, and to compress the space frequencymatrix. Finally, the at least one processor is also configured todetermine a compressed PMI based, at least in part, on the spacefrequency matrix.

Another embodiment is a method that includes the following steps. Themethod includes receiving a CSI report, where the CSI report includes achannel quality indicator (CQI), a rank indicator (RI), and a precodingmatrix indicator (PMI). The method further includes constructing aprecoding matrix based on a linear combination of a plurality ofmutually orthogonal digital Fourier transformation (DFT) spatial beams,and determining a number of bits for the PMI of the precoding matrix.The method also includes determining a space frequency matrix based, atleast in part, on the number of bits for the PMI and the precodingmatrix, and compressing the space frequency matrix. Finally, the methoddetermines a compressed PMI based, at least in part, on the spacefrequency matrix.

Another embodiment is described that is computer-readable media (CRM)comprising computer instructions, where upon execution of the computerinstructions by one or more processors, causes the one or moreprocessors to perform various steps. These steps include receiving a CSIreport, where the CSI report includes a channel quality indicator (CQI),a rank indicator (RI), and a precoding matrix indicator (PMI). The stepsfurther include constructing a precoding matrix based on a linearcombination of a plurality of mutually orthogonal digital Fouriertransformation (DFT) spatial beams, and determining a number of bits forthe PMI of the precoding matrix. The steps also include determining aspace frequency matrix based, at least in part, on the number of bitsfor the PMI and the precoding matrix, and compressing the spacefrequency matrix. Finally, the steps include determining a compressedPMI based, at least in part, on the space frequency matrix.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a W1W2 representation of a precoding matrix inaccordance with some embodiments.

FIG. 2 illustrates a representation of a precoding matrix usingspace-frequency matrix in accordance with some embodiments.

FIG. 3 illustrates a representation of compression of a space-frequencymatrix using linear transformation in accordance with some embodiments.

FIG. 4 depicts an architecture of a system of a network in accordancewith some embodiments.

FIG. 5 depicts an architecture of a system including a first corenetwork in accordance with some embodiments.

FIG. 6 depicts an architecture of a system including a second corenetwork in accordance with some embodiments.

FIG. 7 depicts an example of infrastructure equipment in accordance withvarious embodiments.

FIG. 8 depicts example components of a computer platform in accordancewith various embodiments

FIG. 9 depicts example components of baseband circuitry and radiofrequency circuitry in accordance with various embodiments.

FIG. 10 is an illustration of various protocol functions that may beused for various protocol stacks in accordance with various embodiments.

FIG. 11 illustrates components of a core network in accordance withvarious embodiments.

FIG. 12 is a block diagram illustrating components, according to someexample embodiments, of a system to support network functionsvirtualization (NFV).

FIG. 13 depicts a block diagram illustrating components, according tosome example embodiments, able to read instructions from amachine-readable or computer-readable medium (e.g., a non-transitorymachine-readable storage medium) and perform any one or more of themethodologies discussed herein.

FIG. 14 depicts an example procedure for practicing the variousembodiments discussed herein.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.The same reference numbers may be used in different drawings to identifythe same or similar elements. In the following description, for purposesof explanation and not limitation, specific details are set forth suchas particular structures, architectures, interfaces, techniques, etc. inorder to provide a thorough understanding of the various aspects ofvarious embodiments. However, it will be apparent to those skilled inthe art having the benefit of the present disclosure that the variousaspects of the various embodiments may be practiced in other examplesthat depart from these specific details. In certain instances,descriptions of well-known devices, circuits, and methods are omitted soas not to obscure the description of the various embodiments withunnecessary detail. For the purposes of the present document, the phrase“A or B,” “at least one of A or B,” “one or more of A and B,” and “A/B”means (A), (B), or (A and B).

5G NR and LTE physical layer support codebooks with higher spatialresolution based on linear combination of multiple mutually orthogonaldigital Fourier transformation (DFT) beams. Such codebooks include 5G NRType II Codebook, 5G NR Type II Port Selection Codebook, and LTE advanceCSI codebook. High spatial resolution of such codebooks is achieved byan increased number of bits required for Precoding Matrix Indicator(PMI) reporting.

Embodiments described herein are directed to solutions for decreasingthe number of bits required for PMI reporting for codebooks with higherspatial resolution based on linear combination of DFT beams areproposed. The solutions presented in one or more embodiments presentedherein are based on frequency domain compression utilizing correlationof beam combining coefficients in frequency domain.

The existing solutions to decrease the number of bits required forreporting of PMI for codebooks with higher spatial resolution based onlinear combination of multiple mutually orthogonal DFT beams are basedon the following operations:

-   -   Singular value decomposition (SVD) of space frequency matrix.    -   Linear matrix transformation of space frequency matrix.

There are several disadvantages of the existing solutions. Onedisadvantage is that many details of frequency domain channel stateinformation (CSI) compression are missing, including the following:

-   -   Detailed definition of space frequency matrix.    -   Definition of basis for linear transformation.    -   Quantization method of compressed space frequency matrix.    -   Details of CSI reporting.

Embodiments set forth herein describe details of frequency domain CSIcompression, including:

-   -   Definition of space frequency matrix.    -   Definition of basis matrix.    -   Detailed CSI components for frequency domain CSI compression,        including definition of new CSI components.    -   Details of quantization scheme for newly introduced CSI        components.    -   Details of CSI reporting for newly introduced CSI components.    -   A method of CSI quantization (hybrid time-frequency quantization        of spatial coefficients).

Several advantages are attributable the embodiments set forth herein.For example, one or more embodiments set forth herein assists withdecreasing overhead of PMI reporting for Type II codebooks, which isbeneficial for performance of 5G NR cellular systems.

Embodiments set forth herein can be a part of the following features, ifadopted by 3GPP RAN1 WG:

-   -   5G NR Type II Codebook (3GPP TS 38.214, 3GPP TS 38.212),    -   5G NR Type II Port Selection Codebook (3GPP TS 38.214, 3GPP TS        38.212), LTE Advanced CSI codebook (3GPP TS 36.213, 3GPP TS        36.212).

Embodiments set forth herein can be specified in the followingdocuments, if adopted by 3GPP RAN1 WG:

-   -   3GPP TS 38.214,    -   3GPP TS 38.212,    -   3GPP TS 36.213, and    -   3GPP TS 36.212.        Channel State Information (CSI) Feedback

CSI feedback is used in LTE and 5G NR systems to assist scheduling, linkadaptation, precoding, and spatial multiplexing operations for downlink(DL) transmission. CSI report is transmitted from user equipment (UE) tonext generation NodeB (gNB) or evolved NodeB (eNB) via physical uplinkcontrol channel (PUCCH) or physical uplink shared channel (PUSCH).

There are three main components of a CSI report:

-   -   Channel quality indicator (CQI), which contains information on        the modulation and coding scheme recommended by the user        equipment (UE) for downlink (DL) transmission;    -   Rank indicator (RI), which contains information on the number of        spatial layers recommended by the UE for DL transmission; and    -   Precoding matrix indicator (PMI), which contains information on        the precoding matrix recommended by the UE for DL transmission.        PMI is a set of indexes corresponding to a specific precoding        matrix from a specified finite set of precoding matrixes called        codebook. RI determines the rank of the precoding matrix.        DFT Spatial Beams

5G NR and LTE codebooks are optimized for uniform rectangular planarantenna arrays with cross-polarized antennas and based on DFT spatialbeams v_(l,m) defined by the following equation:

$\begin{matrix}{u_{m} = \left\lbrack {1e^{j\frac{2\pi m}{O_{2}N_{2}}}\ldots e^{j\frac{2\pi{m({N_{2} - 1})}}{O_{2}N_{2}}}} \right\rbrack} & (1)\end{matrix}$$v_{l,m} = \left\lbrack {u_{m}e^{j\frac{2\pi l}{O_{1}N_{1}}}u_{m}\ldots e^{j\frac{2\pi{l({N_{1} - 1})}}{O_{1}N_{1}}}u_{m}} \right\rbrack^{T}$where N₁, N₂ is number of cross-polarized antenna elements in first andsecond dimension respectively, O₁, O₂ is oversampling factors in firstand second dimension respectively, l=0, 1, . . . , (N₁O₁−1)—index whichdetermines spatial beam direction in first dimension, m=0, 1, . . . ,(N₂O₂−1)—index which determines spatial beam direction in seconddimension.

There are also 5G NR and LTE codebooks, which are optimized forbeamformed or precoded CSI reference signals (CSI-RS). In this case,port selection vectors bn are used instead of DFT spatial beams, whereonly n-th element of vector bn is equal to 1 and where other elementsare equal to 0, n=0, 1, . . . , N_(p), N_(p)—number of CSI-RS ports withthe same polarization.

5G NR and LTE Codebooks

5G NR and LTE codebooks can be divided in two groups:

-   -   Codebooks with normal spatial resolution based on selection of        DFT spatial beam.    -   Codebooks with high spatial resolution based on linear        combination DFT spatial beams.

Codebooks with high spatial resolution based on linear combination ofDFT spatial beams include the following 5G NR codebooks: Type IICodebook, Type II Port Selection Codebook.

Codebooks with high spatial resolution based on linear combination ofDFT spatial beams include the following LTE codebook: advanced CSIcodebook.

Codebooks with High Spatial Resolution Based on Beam Linear Combination

A precoding matrix of a codebook with high spatial resolution isconstructed as a linear combination of L mutually orthogonal DFT spatialbeams. A column of precoding matrix with beam combination structure isrepresented in (3) for rank 1 and (4) for rank 2.

$\begin{matrix}{W_{q_{1},q_{2},{n_{1}n_{2}},p_{l}^{(1)},p_{l}^{(2)},c_{l}}^{l} = {\frac{1}{\sqrt{N_{1}N_{2}{\sum\limits_{i = 0}^{{2L} - 1}\left( {p_{l,i}^{(1)}p_{l,i}^{(2)}} \right)^{2}}}}\begin{bmatrix}{\sum\limits_{i = 0}^{L - 1}{v_{m_{1}^{(i)},m_{2}^{(i)}}p_{l.i}^{(1)}p_{l,i}^{(2)}\varphi_{l,i}}} \\{\sum\limits_{i = 0}^{L - 1}{v_{m_{1}^{(i)},m_{2}^{(i)}}p_{{l.i} + L}^{(1)}p_{l,{i + L}}^{(2)}\varphi_{l,{i + L}}}}\end{bmatrix}}} & (2)\end{matrix}$ $\begin{matrix}{W_{q_{1},q_{2},{n_{1}n_{2}},p_{l}^{(1)},p_{l}^{(2)},i_{2,1,1}}^{(1)} = W_{q_{1},q_{2},{n_{1}n_{2}},p_{l}^{(1)},p_{l}^{(2)},i_{2,1,1}}^{1}} & (3)\end{matrix}$ $\begin{matrix}{W_{q_{1},q_{2},{n_{1}n_{2}},p_{1}^{(1)},p_{1}^{(2)},i_{2,1,1},p_{2}^{(1)},p_{2}^{(2)},i_{2,1,2}}^{(2)} = {\frac{1}{\sqrt{2}}\left\lbrack {W_{q_{1},q_{2},{n_{1}n_{2}},p_{1}^{(1)},p_{1}^{(2)},i_{2,1,1}}^{1}W_{q_{1},q_{2},{n_{1}n_{2}},p_{2}^{(1)},p_{2}^{(2)},i_{2,1,2}}^{2}} \right\rbrack}} & (4)\end{matrix}$where q₁, q₂, n₁, n₂ indexes determines the set of L DFT spatial beamsv_(m) ₁ _((i)) _(,m) ₂ _((i)) used in beam combination, i=0, 1, . . . ,L−1—index of DFT spatial beam in the beam combination, l=1, 2— index oflayer, p_(l,k) ⁽¹⁾—wideband amplitude coefficients, p_(l,k) ⁽¹⁾—subbandamplitude coefficients, φ_(l,k)—phase coefficients, k=0, 1, . . . ,(2·L−1)—index of coefficient in beam linear combination, p_(l) ⁽¹⁾ andp_(l) ⁽²⁾—set of indexes determining wideband and subband amplitudecoefficients respectively, c_(l)—set of indexes determining phasecoefficients.

The number of beams in linear combination L can be configured by higherlayers and/or specified in the specification of physical layer.

The number of bits required for reporting and quantization scheme ofwideband and subband amplitude coefficients and phase coefficients canbe fixed configured by higher layers and/or specified in thespecification of physical layer.

If UE reports that p_(l,k) ⁽¹⁾=0, subband amplitude coefficients andphase coefficients are not reported.

5G NR Type II Codebooks Configuration

The number of spatial beams used in linear combination L is configuredwith the higher layer parameter numberOfBeams, L={2,3,4}.

The number of bits and quantization scheme for reporting of phasecoefficients is configured with the higher layer parameterphaseAlphabetSize, where supported quantization schemes are QPSK and8-PSK.

The number of bits required for reporting of wideband amplitudecoefficients is 3 bits.

The number of bits required for reporting of sub-band amplitudecoefficients is controlled by the higher layer parametersub-bandAmplitude set to ‘true’ (1 bit) or ‘false’ (0 bits).

Overhead of PMI Reporting for Codebooks Based on Beam Combining

The number of bits for PMI reporting for codebooks based on linearcombination of DFT spatial beams can be calculated using (5).N _(bits) =N _(beams)+2L·R·N _(amplWB)+2L·R·N _(amplSB)+2L·R·N _(SB) ·N_(phase)  (5)where N_(beams) is the number of bits required for reporting of indexesof L mutually orthogonal beams, R is the rank value or number of layers,N_(amplWB) is the number of bits required for reporting of a widebandamplitude coefficient, N_(SB) is the number of sub-bands configured forCSI reporting, N_(amplWB) is the number of bits required for reportingof a sub-band amplitude coefficient, N_(phase) is the number of bitsrequired for reporting of a phase coefficient.Space Frequency Matrix

The equation for a precoding matrix (2, 3, 4) can be represented insimplified form with dual-stage structure (6).W(k)=W ₁ ·W ₂(k)  (6)where W(k)—precoding matrix for rank R and frequency resource k withdimensions 2N₁N₂×R, W₁—matrix with wideband channel information withdimensions 2N₁N₂×2L, W₂(k)—matrix with sub-band channel information forfrequency resource k with dimensions 2L×R, k—index of sub-band, k=1, 2,. . . , N. In one embodiment, frequency resource is a sub-bandconfigured for CSI reporting.

In order to do frequency domain compression, a precoding matrix can berepresented in alternative form (7).Y(l)=W ₁ ·Y ₂(l)  (7)where column k of Y(l) corresponds to layer l of precoding matrix for afrequency resource k, matrix Y(l) has dimensions 2N₁N₂×N, Y₂(l) is spacefrequency matrix for spatial layer l with dimensions 2L×N, l=1, 2, . . ., R—index of spatial layer.

Equations (6) and (7) are schematically represented in FIG. 1 and FIG. 2respectively. FIG. 1 illustrates a W1W2 representation of a precodingmatrix in accordance with some embodiments. FIG. 2 illustrates arepresentation of a precoding matrix using a space-frequency matrix inaccordance with some embodiments.

Compression of Space Frequency Matrix

Overhead reduction of PMI reporting can be achieved by frequency domainor time domain compression of space frequency matrix Y₂(l). Withoutcompression of space frequency matrix phase and amplitude of eachcoefficient of space frequency matrix are quantized and reported by theUE.

In one embodiment, space frequency matrix can be compressed using lineartransformation. The linear transformation corresponds to the equation(8) and it is schematically represented in FIG. 3 .Y ₂(l)=Z ₁(l)·Z ₂(l)  (8)where Z₁(l)—matrix with coefficients of linear transformation withdimensions 2L×M, Z₂(l)—basis matrix of linear transformation withdimensions M×N. M is total number of vectors in the basis, N is numberof frequency resources.

FIG. 3 illustrates a representation of compression of a space-frequencymatrix using linear transformation in accordance with some embodiments.

In one embodiment, M=M₁·O, where O—oversampling factor.

In one embodiment, oversampling factor is configured by higher layers.

In one embodiment, M₁ is number of frequency resources.

In one embodiment, frequency resource is a sub-band configured for CSIreporting.

In one embodiment, frequency resource is a sub-band within the activebandwidth part.

In one embodiment, frequency resource is a physical resource block (PRB)configured for CSI reporting.

In one embodiment, frequency resource is a PRB in the active bandwidthpart.

In order to simplify further description linear transformation of spacefrequency matrix Y₂(l) is represented by equation (9) as linearcombination of basis vectors.

$\begin{matrix}{{{Y_{2}(l)} = \begin{bmatrix}y_{1}^{(l)} \\y_{2}^{(l)} \\ \vdots \\y_{2L}^{(l)}\end{bmatrix}};{y_{i}^{(l)} = {\sum\limits_{s = 0}^{S - 1}{a_{s,i,l}z_{g_{s,i,l}}}}}} & (9)\end{matrix}$where z_(m)—row of basis matrix Z₂(r) with index m or basis vector m,m=1, 2, . . . , M, S—number of basis vectors in linear combination,g_(s,i,l), s=0, 1, . . . , S−1—indexes of basis vectors in linearcombination, a_(s,i,l)—coefficients of linear combination, i=1, 2, . . ., 2L—index of DFT beam and polarization, l=1, 2, . . . , R—index ofspatial layer.

In one embodiment, a row of basis matrix of linear transformation Z₂(r)is DFT vector z_(m) (10).

$\begin{matrix}{z_{m} = \left\lbrack {1e^{j\frac{2\pi m}{N}}\ldots e^{j\frac{2\pi{m({N_{1} - 1})}}{M}}} \right\rbrack} & (10)\end{matrix}$

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are reported by a UE.

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are different for different DFT beams and differentpolarizations.

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are same for different DFT beams and different polarizationsg_(s,i,l)=g_(s,j,l), i=1, 2, . . . , 2L, j=1, 2, . . . , 2L.

In one embodiment, indexes of basis vectors in linear combination aresame for a DFT beam and different polarizations g_(s,i,l)=g_(s,j,l),i=1, 2, . . . , L, j=i+L.

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are different for different layers.

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are same for different layers g_(s,i,l)=g_(s,j,l), l=1, 2, . .. , R, j=1, 2, . . . , R.

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are reported by a UE separately for s=0, 1, . . . , S−1.

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are reported by a UE jointly for s=0, 1, . . . , S−1 by usingindex of combination G_(i,l) (11).

$\begin{matrix}{G_{i,l} = {\sum\limits_{s = 0}^{S - 1}{C\left( {{M - 1 - g_{s,i,l}},{S - s}} \right)}}} & (11)\end{matrix}$

where g_(s,i,l) increases as s increases, C(x,y)—combinatorialcoefficients (e.g. table 1).

TABLE 1 Combinatorial coefficients C(x, y) y x 1 2 3 4 0 0 0 0 0 1 1 0 00 2 2 1 0 0 3 3 3 1 0 4 4 6 4 1 5 5 10 10 5 6 6 15 20 15 7 7 21 35 35 88 28 56 70 9 9 36 84 126 10 10 45 120 210 11 11 55 165 330 12 12 66 220495 13 13 78 286 715 14 14 91 364 1001 15 15 105 455 1365

In one embodiment number of basis vectors in linear combination S isconfigured by higher layers.

In one embodiment S equals to M.

In one embodiment S is a function of M.

In one embodiment S equals to N.

In one embodiment S is a function of N.

In one embodiment, S is configured separately for different codebookrank value.

In one embodiment, S is configured separately for different spatiallayers.

Quantization of CSI Components

In one embodiment amplitudes and phases of coefficients of linearcombination a_(s,i,l) are quantized and reported by a UE. In oneembodiment phases of coefficients of linear combination a_(s,i,l) arequantized and reported by a UE. In one embodiment phases of coefficientsof linear combination are quantized using set of values values{e^(j2πm/N) ^(PSK) }, m=0, 1, . . . , N_(PSK)−1. In one embodimentquantization scheme of phases of coefficients of linear combinationa_(s,i,l) is configured by higher layers. In one embodiment N_(PSK) isconfigured by higher layers. In one embodiment amplitudes ofcoefficients of linear combination a_(s,i,l) are quantized and reportedby a UE. In one embodiment amplitudes of coefficients of linearcombination a_(s,i,l) are quantized using of values

$\left\{ \left\lbrack {\frac{1}{2^{n/2}},0} \right\rbrack \right\},$n=0, 1, . . . , N_(a)−2. In one embodiment amplitudes of coefficients oflinear combination a_(s,i,l) are quantized using of values

$\left\{ \left\lbrack {\frac{1}{2^{n}},0} \right\rbrack \right\},$n=0, 1, . . . , N_(a)−2.

In one embodiment quantization scheme of phases of coefficients oflinear combination a_(s,i,l) is configured by higher layers. In oneembodiment N_(a) is configured by higher layers. In one embodiment,leading coefficients of linear combination A_(i,l) is reported by a UE.In one embodiment, index of leading coefficients is reported by a UE. Inone embodiment, ratios of amplitudes of a coefficient of linearcombination and amplitude of leading coefficient of linear combination|a_(s,i,l)|/|A_(i,l)| are reported by a UE. In one embodiment, ratios ofamplitudes of a coefficient of linear combination and amplitude ofleading coefficient of linear combination |a_(s,i,l)|/|A_(i,l)| arequantized using of values

$\left\{ \left\lbrack {\frac{1}{2^{n/2}},0} \right\rbrack \right\},$n=0, 1, . . . , N_(a)−2. In one embodiment, ratios of amplitudes of acoefficient of linear combination and amplitude of leading coefficientof linear combination |a_(s,i,l)|/|A_(i,l)| are quantized using ofvalues

$\left\{ \left\lbrack {\frac{1}{2^{n}},0} \right\rbrack \right\},$n=0, 1, . . . , N_(a)−2.

In one embodiment, phase of product of a coefficient of linearcombination and complex conjugate of leading coefficient of linearcombination a_(s,i,l)·A_(i,l)* is reported by a UE.

In one embodiment, index of leading coefficients of linear combinationis reported by a UE for each DFT beam and polarization and for eachspatial layer.

In one embodiment, same index of leading coefficients of linearcombination is reported by a UE for different DFT beams andpolarizations.

CSI Reporting

5G NR Type II codebook is reported via PUSCH. PUSCH based CSI reportscomprise two parts: CSI part 1 and CSI part 2. CSI parts are separatelyencoded and transmitted using mutually orthogonal resource elements. Thepayload size of CSI part 1 is fixed for a given CSI configuration. Thepayload size of CSI part 2 depends on the content of CSI part 1.

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are reported in CSI part 1.

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are reported in CSI part 2.

In one embodiment, indexes of basis vectors in linear combinationg_(s,i,l) are reported in CSI part 1 for 1^(st) spatial layer (l=1) andin CSI part 2 for 2^(nd) spatial layer (l=2).

In one embodiment, amplitudes of coefficients of linear combinationa_(s,i,l) are reported in CSI part 1.

In one embodiment, amplitudes of coefficients of linear combinationa_(s,i,l) are reported in CSI part 2.

In one embodiment, amplitudes of coefficients of linear combinationa_(s,i,l) are reported in CSI part 1 for 1^(st) spatial layer (l=1) andin CSI part 2 for 2^(nd) spatial layer (l=2).

In one embodiment, the number of coefficients of linear combinationa_(s,i,l) with non-zero amplitude is reported in CSI part 1.

In one embodiment, the number of coefficients of linear combinationa_(s,i,l) with 0 amplitude is reported in CSI part 1.

In one embodiment, the number of coefficients of linear combinationa_(s,i,l) with non-zero amplitude is reported in CSI part 1 for spatiallayer l. In one embodiment, the number of coefficients of linearcombination with 0 amplitude is reported in CSI part 1 for spatial layerl.

In one embodiment, leading coefficients of linear combination A_(i,l) isreported in CSI part 1. In one embodiment, leading coefficients oflinear combination A_(i,l) is reported in CSI part 1. In one embodiment,leading coefficients of linear combination A_(i,l) is reported in CSIpart 1 for 1^(st) spatial layer (l=1) and in CSI part 2 for 2^(nd)spatial layer (l=2).

In one embodiment, ratios of amplitudes of a coefficient of linearcombination and amplitude of leading coefficient of linear combination|a_(s,i,l)|/|A_(i,l)| are reported in CSI part 1. In one embodiment,ratios of amplitudes of a coefficient of linear combination andamplitude of leading coefficient of linear combination|a_(s,i,l)|/|A_(i,l)| are reported in CSI part 2.

In one embodiment, ratios of amplitudes of a coefficient of linearcombination and amplitude of leading coefficient of linear combination|a_(s,i,l)|/|A_(i,l)| are reported in CSI part 1 for 1^(st) spatiallayer (l=1) and in CSI part 2 for 2^(nd) spatial layer (l=2).

Hybrid Time-Frequency Quantization of Spatial Coefficients

In one embodiment, space frequency matrix Y₂(l) is reported by a UEusing hybrid time-frequency quantization. In one embodiment, subset ofrows of space-frequency matrix {y_(i) ^((l))} is quantized and reportedas linear combination of basis vectors (9) and other rows ofspace-frequency matrix y_(j) ^((l)) are quantized and reported usingphase and/or amplitude quantization and reporting of each element ofthis rows. In one embodiment, the subset of rows of space frequencymatrix {y_(i) ^((l))} is determined based on average amplitude ofelements of rows of space frequency matrix. In one embodiment, thenumber of rows of space frequency matrix in the subset {y_(i) ^((l))} isconfigured by higher layers.

Reporting of Coefficients Associated with the StrongestBeam/Polarization

Since SVD vectors and Eigen vectors are defined up to multiplication bya unit-phase factor the performance of MIMO system is the same ifprecoder vectors for kth sub-band is V(k) or e^(jφ)V(k), where e^(jφ) iscomplex exponent with arbitrary phase. This property can be used inorder to achieve better performance frequency domain CSI compressionand/or reduce reporting overhead.

Hence, each column of space frequency matrix Y₂(l) can be multiplied bya complex number with arbitrary phase and unit amplitude. In oneembodiment UE multiplies column k^(th) column of matrix Y₂(l) by q(k)*,k=1, 2, . . . , N. In one embodiment q(k)=c(k)/|c(k)|, where c(k) is therow of space frequency matrix Y₂(l) associated with the strongest DFTbeam/polarization (DFT beam/polarization with the highest average orwideband power). After such operation frequency-domain coefficientsassociated with the strongest DFT beam/polarization are real numbers|c(k)|. Time-domain coefficients associated with the strongest DFTbeam/polarization C(m), m=1, 2, . . . , M, are derived at the UE by DFTwith certain oversampling factor of frequency-domain coefficientsassociated with the strongest DFT beam/polarization |c(k)|.

It can be a priory assumed that frequency-domain coefficients associatedwith the strongest DFT beam/polarization are real to reduce overhead orimprove performance of frequency-domain compression. If frequency-domaincoefficients are real numbers, time-domain coefficients (coefficientsafter multiplication by DFT matrix) have symmetry property and thefollowing equation is valid.C(m)=C*({(−m+1)mod M}+1)  (12)

As it can be seen from the equation (12), some time-domain coefficientscan be derived from other time domain coefficient. In one embodimenttime-domain coefficient associated with the strongest DFTbeam/polarization are divided into two sets C₁ and C₂. In one embodimentC₁ include coefficients C(m) with indexes m≤(M/2+1), C₂ includeremaining coefficients C(m). In one embodiment subset of coefficientsfrom C₁ is reported by the UE. In one embodiment coefficients from C₂are derived based on coefficients from C₁ using predefined equation. Inone example equation (12) is used to derive coefficients from C₂ basedon coefficients from C₁. In one embodiment space frequency matrix Y₂(l)is reconstructed using equation (9) considering time-domain coefficientsfrom C₂ derived based on the reported time-domain coefficients from C₁.

Systems and Implementations

FIG. 4 illustrates an example architecture of a system 400 of a network,in accordance with various embodiments. The following description isprovided for an example system 400 that operates in conjunction with theLTE system standards and 5G or NR system standards as provided by 3GPPtechnical specifications. However, the example embodiments are notlimited in this regard and the described embodiments may apply to othernetworks that benefit from the principles described herein, such asfuture 3GPP systems (e.g., Sixth Generation (6G)) systems, IEEE 802.16protocols (e.g., WMAN, WiMAX, etc.), or the like.

As shown by FIG. 4 , the system 400 includes UE 401 a and UE 401 b(collectively referred to as “UEs 401” or “UE 401”). In this example,UEs 401 are illustrated as smartphones (e.g., handheld touchscreenmobile computing devices connectable to one or more cellular networks),but may also comprise any mobile or non-mobile computing device, such asconsumer electronics devices, cellular phones, smartphones, featurephones, tablet computers, wearable computer devices, personal digitalassistants (PDAs), pagers, wireless handsets, desktop computers, laptopcomputers, in-vehicle infotainment (IVI), in-car entertainment (ICE)devices, an Instrument Cluster (IC), head-up display (HUD) devices,onboard diagnostic (OBD) devices, dashtop mobile equipment (DME), mobiledata terminals (MDTs), Electronic Engine Management System (EEMS),electronic/engine control units (ECUs), electronic/engine controlmodules (ECMs), embedded systems, microcontrollers, control modules,engine management systems (EMS), networked or “smart” appliances, MTCdevices, M2M, IoT devices, and/or the like.

In some embodiments, any of the UEs 401 may be IoT UEs, which maycomprise a network access layer designed for low-power IoT applicationsutilizing short-lived UE connections. An IoT UE can utilize technologiessuch as M2M or MTC for exchanging data with an MTC server or device viaa PLMN, ProSe or D2D communication, sensor networks, or IoT networks.The M2M or MTC exchange of data may be a machine-initiated exchange ofdata. An IoT network describes interconnecting IoT UEs, which mayinclude uniquely identifiable embedded computing devices (within theInternet infrastructure), with short-lived connections. The IoT UEs mayexecute background applications (e.g., keep-alive messages, statusupdates, etc.) to facilitate the connections of the IoT network.

The UEs 401 may be configured to connect, for example, communicativelycouple, with an or RAN 410. In embodiments, the RAN 410 may be an NG RANor a 5G RAN, an E-UTRAN, or a legacy RAN, such as a UTRAN or GERAN. Asused herein, the term “NG RAN” or the like may refer to a RAN 410 thatoperates in an NR or 5G system 400, and the term “E-UTRAN” or the likemay refer to a RAN 410 that operates in an LTE or 4G system 400. The UEs401 utilize connections (or channels) 403 and 404, respectively, each ofwhich comprises a physical communications interface or layer (discussedin further detail below).

In this example, the connections 403 and 404 are illustrated as an airinterface to enable communicative coupling, and can be consistent withcellular communications protocols, such as a GSM protocol, a CDMAnetwork protocol, a PTT protocol, a POC protocol, a UMTS protocol, a3GPP LTE protocol, a 5G protocol, a NR protocol, and/or any of the othercommunications protocols discussed herein. In embodiments, the UEs 401may directly exchange communication data via a ProSe interface 405. TheProSe interface 405 may alternatively be referred to as a SL interface405 and may comprise one or more logical channels, including but notlimited to a PSCCH, a PSSCH, a PSDCH, and a PSBCH.

The UE 401 b is shown to be configured to access an AP 406 (alsoreferred to as “WLAN node 406,” “WLAN 406,” “WLAN Termination 406,” “WT406” or the like) via connection 407. The connection 407 can comprise alocal wireless connection, such as a connection consistent with any IEEE802.11 protocol, wherein the AP 406 would comprise a wireless fidelity(Wi-Fi®) router. In this example, the AP 406 is shown to be connected tothe Internet without connecting to the core network of the wirelesssystem (described in further detail below). In various embodiments, theUE 401 b, RAN 410, and AP 406 may be configured to utilize LWA operationand/or LWIP operation. The LWA operation may involve the UE 401 b inRRC_CONNECTED being configured by a RAN node 411 a-b to utilize radioresources of LTE and WLAN. LWIP operation may involve the UE 401 b usingWLAN radio resources (e.g., connection 407) via IPsec protocol tunnelingto authenticate and encrypt packets (e.g., IP packets) sent over theconnection 407. IPsec tunneling may include encapsulating the entiretyof original IP packets and adding a new packet header, therebyprotecting the original header of the IP packets.

The RAN 410 can include one or more AN nodes or RAN nodes 411 a and 411b (collectively referred to as “RAN nodes 411” or “RAN node 411”) thatenable the connections 403 and 404. As used herein, the terms “accessnode,” “access point,” or the like may describe equipment that providesthe radio baseband functions for data and/or voice connectivity betweena network and one or more users. These access nodes can be referred toas BS, gNB s, RAN nodes, eNBs, NodeBs, RSUs, TRxPs or TRPs, and soforth, and can comprise ground stations (e.g., terrestrial accesspoints) or satellite stations providing coverage within a geographicarea (e.g., a cell). As used herein, the term “NG RAN node” or the likemay refer to a RAN node 411 that operates in an NR or 5G system 400 (forexample, a gNB), and the term “E-UTRAN node” or the like may refer to aRAN node 411 that operates in an LTE or 4G system 400 (e.g., an eNB).According to various embodiments, the RAN nodes 411 may be implementedas one or more of a dedicated physical device such as a macrocell basestation, and/or a low power (LP) base station for providing femtocells,picocells or other like cells having smaller coverage areas, smalleruser capacity, or higher bandwidth compared to macrocells.

In some embodiments, all or parts of the RAN nodes 411 may beimplemented as one or more software entities running on server computersas part of a virtual network, which may be referred to as a CRAN and/ora virtual baseband unit pool (vBBUP). In these embodiments, the CRAN orvBBUP may implement a RAN function split, such as a PDCP split whereinRRC and PDCP layers are operated by the CRAN/vBBUP and other L2 protocolentities are operated by individual RAN nodes 411; a MAC/PHY splitwherein RRC, PDCP, RLC, and MAC layers are operated by the CRAN/vBBUPand the PHY layer is operated by individual RAN nodes 411; or a “lowerPHY” split wherein RRC, PDCP, RLC, MAC layers and upper portions of thePHY layer are operated by the CRAN/vBBUP and lower portions of the PHYlayer are operated by individual RAN nodes 411. This virtualizedframework allows the freed-up processor cores of the RAN nodes 411 toperform other virtualized applications. In some implementations, anindividual RAN node 411 may represent individual gNB-DUs that areconnected to a gNB-CU via individual F1 interfaces (not shown by FIG. 4). In these implementations, the gNB-DUs may include one or more remoteradio heads or RFEMs (see, e.g., FIG. 7 ), and the gNB-CU may beoperated by a server that is located in the RAN 410 (not shown) or by aserver pool in a similar manner as the CRAN/vBBUP. Additionally oralternatively, one or more of the RAN nodes 411 may be next generationeNBs (ng-eNBs), which are RAN nodes that provide E-UTRA user plane andcontrol plane protocol terminations toward the UEs 401, and areconnected to a 5GC (e.g., CN 620 of FIG. 6 ) via an NG interface(discussed infra).

In V2X scenarios one or more of the RAN nodes 411 may be or act as RSUs.The term “Road Side Unit” or “RSU” may refer to any transportationinfrastructure entity used for V2X communications. An RSU may beimplemented in or by a suitable RAN node or a stationary (or relativelystationary) UE, where an RSU implemented in or by a UE may be referredto as a “UE-type RSU,” an RSU implemented in or by an eNB may bereferred to as an “eNB-type RSU,” an RSU implemented in or by a gNB maybe referred to as a “gNB-type RSU,” and the like. In one example, an RSUis a computing device coupled with radio frequency circuitry located ona roadside that provides connectivity support to passing vehicle UEs 401(vUEs 401). The RSU may also include internal data storage circuitry tostore intersection map geometry, traffic statistics, media, as well asapplications/software to sense and control ongoing vehicular andpedestrian traffic. The RSU may operate on the 5.9 GHz Direct ShortRange Communications (DSRC) band to provide very low latencycommunications required for high speed events, such as crash avoidance,traffic warnings, and the like. Additionally or alternatively, the RSUmay operate on the cellular V2X band to provide the aforementioned lowlatency communications, as well as other cellular communicationsservices. Additionally or alternatively, the RSU may operate as a Wi-Fihotspot (2.4 GHz band) and/or provide connectivity to one or morecellular networks to provide uplink and downlink communications. Thecomputing device(s) and some or all of the radiofrequency circuitry ofthe RSU may be packaged in a weatherproof enclosure suitable for outdoorinstallation, and may include a network interface controller to providea wired connection (e.g., Ethernet) to a traffic signal controllerand/or a backhaul network.

Any of the RAN nodes 411 can terminate the air interface protocol andcan be the first point of contact for the UEs 401. In some embodiments,any of the RAN nodes 411 can fulfill various logical functions for theRAN 410 including, but not limited to, radio network controller (RNC)functions such as radio bearer management, uplink and downlink dynamicradio resource management and data packet scheduling, and mobilitymanagement.

In embodiments, the UEs 401 can be configured to communicate using OFDMcommunication signals with each other or with any of the RAN nodes 411over a multicarrier communication channel in accordance with variouscommunication techniques, such as, but not limited to, an OFDMAcommunication technique (e.g., for downlink communications) or a SC-FDMAcommunication technique (e.g., for uplink and ProSe or sidelinkcommunications), although the scope of the embodiments is not limited inthis respect. The OFDM signals can comprise a plurality of orthogonalsubcarriers.

In some embodiments, a downlink resource grid can be used for downlinktransmissions from any of the RAN nodes 411 to the UEs 401, while uplinktransmissions can utilize similar techniques. The grid can be atime-frequency grid, called a resource grid or time-frequency resourcegrid, which is the physical resource in the downlink in each slot. Sucha time-frequency plane representation is a common practice for OFDMsystems, which makes it intuitive for radio resource allocation. Eachcolumn and each row of the resource grid corresponds to one OFDM symboland one OFDM subcarrier, respectively. The duration of the resource gridin the time domain corresponds to one slot in a radio frame. Thesmallest time-frequency unit in a resource grid is denoted as a resourceelement. Each resource grid comprises a number of resource blocks, whichdescribe the mapping of certain physical channels to resource elements.Each resource block comprises a collection of resource elements; in thefrequency domain, this may represent the smallest quantity of resourcesthat currently can be allocated. There are several different physicaldownlink channels that are conveyed using such resource blocks.

According to various embodiments, the UEs 401, 402 and the RAN nodes411, 412 communicate data (for example, transmit and receive) data overa licensed medium (also referred to as the “licensed spectrum” and/orthe “licensed band”) and an unlicensed shared medium (also referred toas the “unlicensed spectrum” and/or the “unlicensed band”). The licensedspectrum may include channels that operate in the frequency range ofapproximately 400 MHz to approximately 3.8 GHz, whereas the unlicensedspectrum may include the 5 GHz band.

To operate in the unlicensed spectrum, the UEs 401, 402 and the RANnodes 411, 412 may operate using LAA, eLAA, and/or feLAA mechanisms. Inthese implementations, the UEs 401, 402 and the RAN nodes 411, 412 mayperform one or more known medium-sensing operations and/orcarrier-sensing operations in order to determine whether one or morechannels in the unlicensed spectrum is unavailable or otherwise occupiedprior to transmitting in the unlicensed spectrum. The medium/carriersensing operations may be performed according to a listen-before-talk(LBT) protocol.

LBT is a mechanism whereby equipment (for example, UEs 401, 402, RANnodes 411, 412, etc.) senses a medium (for example, a channel or carrierfrequency) and transmits when the medium is sensed to be idle (or when aspecific channel in the medium is sensed to be unoccupied). The mediumsensing operation may include CCA, which utilizes at least ED todetermine the presence or absence of other signals on a channel in orderto determine if a channel is occupied or clear. This LBT mechanismallows cellular/LAA networks to coexist with incumbent systems in theunlicensed spectrum and with other LAA networks. ED may include sensingRF energy across an intended transmission band for a period of time andcomparing the sensed RF energy to a predefined or configured threshold.

Typically, the incumbent systems in the 5 GHz band are WLANs based onIEEE 802.11 technologies. WLAN employs a contention-based channel accessmechanism, called CSMA/CA. Here, when a WLAN node (e.g., a mobilestation (MS) such as UE 401 or 402, AP 406, or the like) intends totransmit, the WLAN node may first perform CCA before transmission.Additionally, a backoff mechanism is used to avoid collisions insituations where more than one WLAN node senses the channel as idle andtransmits at the same time. The backoff mechanism may be a counter thatis drawn randomly within the CWS, which is increased exponentially uponthe occurrence of collision and reset to a minimum value when thetransmission succeeds. The LBT mechanism designed for LAA is somewhatsimilar to the CSMA/CA of WLAN. In some implementations, the LBTprocedure for DL or UL transmission bursts including PDSCH or PUSCHtransmissions, respectively, may have an LAA contention window that isvariable in length between X and Y ECCA slots, where X and Y are minimumand maximum values for the CWSs for LAA. In one example, the minimum CWSfor an LAA transmission may be 9 microseconds (μs); however, the size ofthe CWS and a MCOT (for example, a transmission burst) may be based ongovernmental regulatory requirements.

The LAA mechanisms are built upon CA technologies of LTE-Advancedsystems. In CA, each aggregated carrier is referred to as a CC. A CC mayhave a bandwidth of 1.4, 3, 5, 10, 15 or 20 MHz and a maximum of fiveCCs can be aggregated, and therefore, a maximum aggregated bandwidth is100 MHz. In FDD systems, the number of aggregated carriers can bedifferent for DL and UL, where the number of UL CCs is equal to or lowerthan the number of DL component carriers. In some cases, individual CCscan have a different bandwidth than other CCs. In TDD systems, thenumber of CCs as well as the bandwidths of each CC is usually the samefor DL and UL.

CA also comprises individual serving cells to provide individual CCs.The coverage of the serving cells may differ, for example, because CCson different frequency bands will experience different pathloss. Aprimary service cell or PCell may provide a PCC for both UL and DL, andmay handle RRC and NAS related activities. The other serving cells arereferred to as SCells, and each SCell may provide an individual SCC forboth UL and DL. The SCCs may be added and removed as required, whilechanging the PCC may require the UE 401, 402 to undergo a handover. InLAA, eLAA, and feLAA, some or all of the SCells may operate in theunlicensed spectrum (referred to as “LAA SCells”), and the LAA SCellsare assisted by a PCell operating in the licensed spectrum. When a UE isconfigured with more than one LAA SCell, the UE may receive UL grants onthe configured LAA SCells indicating different PUSCH starting positionswithin a same subframe.

The PDSCH carries user data and higher-layer signaling to the UEs 401.The PDCCH carries information about the transport format and resourceallocations related to the PDSCH channel, among other things. It mayalso inform the UEs 401 about the transport format, resource allocation,and HARQ information related to the uplink shared channel. Typically,downlink scheduling (assigning control and shared channel resourceblocks to the UE 401 b within a cell) may be performed at any of the RANnodes 411 based on channel quality information fed back from any of theUEs 401. The downlink resource assignment information may be sent on thePDCCH used for (e.g., assigned to) each of the UEs 401.

The PDCCH uses CCEs to convey the control information. Before beingmapped to resource elements, the PDCCH complex-valued symbols may firstbe organized into quadruplets, which may then be permuted using asub-block interleaver for rate matching. Each PDCCH may be transmittedusing one or more of these CCEs, where each CCE may correspond to ninesets of four physical resource elements known as REGs. Four QuadraturePhase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCHcan be transmitted using one or more CCEs, depending on the size of theDCI and the channel condition. There can be four or more different PDCCHformats defined in LTE with different numbers of CCEs (e.g., aggregationlevel, L=1, 2, 4, or 8).

Some embodiments may use concepts for resource allocation for controlchannel information that are an extension of the above-describedconcepts. For example, some embodiments may utilize an EPDCCH that usesPDSCH resources for control information transmission. The EPDCCH may betransmitted using one or more ECCEs. Similar to above, each ECCE maycorrespond to nine sets of four physical resource elements known as anEREGs. An ECCE may have other numbers of EREGs in some situations.

The RAN nodes 411 may be configured to communicate with one another viainterface 412. In embodiments where the system 400 is an LTE system(e.g., when CN 420 is an EPC 520 as in FIG. 5 ), the interface 412 maybe an X2 interface 412. The X2 interface may be defined between two ormore RAN nodes 411 (e.g., two or more eNBs and the like) that connect toEPC 420, and/or between two eNBs connecting to EPC 420. In someimplementations, the X2 interface may include an X2 user plane interface(X2-U) and an X2 control plane interface (X2-C). The X2-U may provideflow control mechanisms for user data packets transferred over the X2interface, and may be used to communicate information about the deliveryof user data between eNBs. For example, the X2-U may provide specificsequence number information for user data transferred from a MeNB to anSeNB; information about successful in sequence delivery of PDCP PDUs toa UE 401 from an SeNB for user data; information of PDCP PDUs that werenot delivered to a UE 401; information about a current minimum desiredbuffer size at the SeNB for transmitting to the UE user data; and thelike. The X2-C may provide intra-LTE access mobility functionality,including context transfers from source to target eNBs, user planetransport control, etc.; load management functionality; as well asinter-cell interference coordination functionality.

In embodiments where the system 400 is a 5G or NR system (e.g., when CN420 is an 5GC 620 as in FIG. 6 ), the interface 412 may be an Xninterface 412. The Xn interface is defined between two or more RAN nodes411 (e.g., two or more gNBs and the like) that connect to 5GC 420,between a RAN node 411 (e.g., a gNB) connecting to 5GC 420 and an eNB,and/or between two eNBs connecting to 5GC 420. In some implementations,the Xn interface may include an Xn user plane (Xn-U) interface and an Xncontrol plane (Xn-C) interface. The Xn-U may provide non-guaranteeddelivery of user plane PDUs and support/provide data forwarding and flowcontrol functionality. The Xn-C may provide management and errorhandling functionality, functionality to manage the Xn-C interface;mobility support for UE 401 in a connected mode (e.g., CM-CONNECTED)including functionality to manage the UE mobility for connected modebetween one or more RAN nodes 411. The mobility support may includecontext transfer from an old (source) serving RAN node 411 to new(target) serving RAN node 411; and control of user plane tunnels betweenold (source) serving RAN node 411 to new (target) serving RAN node 411.A protocol stack of the Xn-U may include a transport network layer builton Internet Protocol (IP) transport layer, and a GTP-U layer on top of aUDP and/or IP layer(s) to carry user plane PDUs. The Xn-C protocol stackmay include an application layer signaling protocol (referred to as XnApplication Protocol (Xn-AP)) and a transport network layer that isbuilt on SCTP. The SCTP may be on top of an IP layer, and may providethe guaranteed delivery of application layer messages. In the transportIP layer, point-to-point transmission is used to deliver the signalingPDUs. In other implementations, the Xn-U protocol stack and/or the Xn-Cprotocol stack may be same or similar to the user plane and/or controlplane protocol stack(s) shown and described herein.

The RAN 410 is shown to be communicatively coupled to a core network—inthis embodiment, core network (CN) 420. The CN 420 may comprise aplurality of network elements 422, which are configured to offer variousdata and telecommunications services to customers/subscribers (e.g.,users of UEs 401) who are connected to the CN 420 via the RAN 410. Thecomponents of the CN 420 may be implemented in one physical node orseparate physical nodes including components to read and executeinstructions from a machine-readable or computer-readable medium (e.g.,a non-transitory machine-readable storage medium). In some embodiments,NFV may be utilized to virtualize any or all of the above-describednetwork node functions via executable instructions stored in one or morecomputer-readable storage mediums (described in further detail below). Alogical instantiation of the CN 420 may be referred to as a networkslice, and a logical instantiation of a portion of the CN 420 may bereferred to as a network sub-slice. NFV architectures andinfrastructures may be used to virtualize one or more network functions,alternatively performed by proprietary hardware, onto physical resourcescomprising a combination of industry-standard server hardware, storagehardware, or switches. In other words, NFV systems can be used toexecute virtual or reconfigurable implementations of one or more EPCcomponents/functions.

Generally, the application server 430 may be an element offeringapplications that use IP bearer resources with the core network (e.g.,UMTS PS domain, LTE PS data services, etc.). The application server 430can also be configured to support one or more communication services(e.g., VoIP sessions, PTT sessions, group communication sessions, socialnetworking services, etc.) for the UEs 401 via the EPC 420.

In embodiments, the CN 420 may be a 5GC (referred to as “5GC 420” or thelike), and the RAN 410 may be connected with the CN 420 via an NGinterface 413. In embodiments, the NG interface 413 may be split intotwo parts, an NG user plane (NG-U) interface 414, which carries trafficdata between the RAN nodes 411 and a UPF, and the S1 control plane(NG-C) interface 415, which is a signaling interface between the RANnodes 411 and AMFs. Embodiments where the CN 420 is a 5GC 420 arediscussed in more detail with regard to FIG. 6 .

In embodiments, the CN 420 may be a 5G CN (referred to as “5GC 420” orthe like), while in other embodiments, the CN 420 may be an EPC). WhereCN 420 is an EPC (referred to as “EPC 420” or the like), the RAN 410 maybe connected with the CN 420 via an S1 interface 413. In embodiments,the S1 interface 413 may be split into two parts, an S1 user plane(S1-U) interface 414, which carries traffic data between the RAN nodes411 and the S-GW, and the S1-MME interface 415, which is a signalinginterface between the RAN nodes 411 and MMEs. An example architecturewherein the CN 420 is an EPC 420 is shown by FIG. 5 .

FIG. 5 illustrates an example architecture of a system 500 including afirst CN 520, in accordance with various embodiments. In this example,system 500 may implement the LTE standard wherein the CN 520 is an EPC520 that corresponds with CN 420 of FIG. 4 . Additionally, the UE 501may be the same or similar as the UEs 401 of FIG. 4 , and the E-UTRAN510 may be a RAN that is the same or similar to the RAN 410 of FIG. 4 ,and which may include RAN nodes 411 discussed previously. The CN 520 maycomprise MMEs 521, an S-GW 522, a P-GW 523, a HSS 524, and a SGSN 525.

The MMEs 521 may be similar in function to the control plane of legacySGSN, and may implement MM functions to keep track of the currentlocation of a UE 501. The MMEs 521 may perform various MM procedures tomanage mobility aspects in access such as gateway selection and trackingarea list management. MM (also referred to as “EPS MM” or “EMM” inE-UTRAN systems) may refer to all applicable procedures, methods, datastorage, etc. that are used to maintain knowledge about a presentlocation of the UE 501, provide user identity confidentiality, and/orperform other like services to users/subscribers. Each UE 501 and theMME 521 may include an MM or EMM sublayer, and an MM context may beestablished in the UE 501 and the MME 521 when an attach procedure issuccessfully completed. The MM context may be a data structure ordatabase object that stores MM-related information of the UE 501. TheMMEs 521 may be coupled with the HSS 524 via an Sha reference point,coupled with the SGSN 525 via an S3 reference point, and coupled withthe S-GW 522 via an S11 reference point.

The SGSN 525 may be a node that serves the UE 501 by tracking thelocation of an individual UE 501 and performing security functions. Inaddition, the SGSN 525 may perform Inter-EPC node signaling for mobilitybetween 2G/3G and E-UTRAN 3GPP access networks; PDN and S-GW selectionas specified by the MMEs 521; handling of UE 501 time zone functions asspecified by the MMEs 521; and MME selection for handovers to E-UTRAN3GPP access network. The S3 reference point between the MMEs 521 and theSGSN 525 may enable user and bearer information exchange for inter-3GPPaccess network mobility in idle and/or active states.

The HSS 524 may comprise a database for network users, includingsubscription-related information to support the network entities'handling of communication sessions. The EPC 520 may comprise one orseveral HSSs 524, depending on the number of mobile subscribers, on thecapacity of the equipment, on the organization of the network, etc. Forexample, the HSS 524 can provide support for routing/roaming,authentication, authorization, naming/addressing resolution, locationdependencies, etc. An Sha reference point between the HSS 524 and theMMEs 521 may enable transfer of subscription and authentication data forauthenticating/authorizing user access to the EPC 520 between HSS 524and the MMEs 521.

The S-GW 522 may terminate the S1 interface 413 (“S1-U” in FIG. 5 )toward the RAN 510, and routes data packets between the RAN 510 and theEPC 520. In addition, the S-GW 522 may be a local mobility anchor pointfor inter-RAN node handovers and also may provide an anchor forinter-3GPP mobility. Other responsibilities may include lawfulintercept, charging, and some policy enforcement. The S11 referencepoint between the S-GW 522 and the MMEs 521 may provide a control planebetween the MMES 521 and the S-GW 522. The S-GW 522 may be coupled withthe P-GW 523 via an S5 reference point.

The P-GW 523 may terminate an SGi interface toward a PDN 530. The P-GW523 may route data packets between the EPC 520 and external networkssuch as a network including the application server 430 (alternativelyreferred to as an “AF”) via an IP interface 425 (see e.g., FIG. 4 ). Inembodiments, the P-GW 523 may be communicatively coupled to anapplication server (application server 430 of FIG. 4 or PDN 530 in FIG.5 ) via an IP communications interface 425 (see, e.g., FIG. 4 ). The S5reference point between the P-GW 523 and the S-GW 522 may provide userplane tunneling and tunnel management between the P-GW 523 and the S-GW522. The S5 reference point may also be used for S-GW 522 relocation dueto UE 501 mobility and if the S-GW 522 needs to connect to anon-collocated P-GW 523 for the required PDN connectivity. The P-GW 523may further include a node for policy enforcement and charging datacollection (e.g., PCEF (not shown)). Additionally, the SGi referencepoint between the P-GW 523 and the packet data network (PDN) 530 may bean operator external public, a private PDN, or an intra operator packetdata network, for example, for provision of IMS services. The P-GW 523may be coupled with a PCRF 526 via a Gx reference point.

PCRF 526 is the policy and charging control element of the EPC 520. In anon-roaming scenario, there may be a single PCRF 526 in the Home PublicLand Mobile Network (HPLMN) associated with a UE 501's Internet ProtocolConnectivity Access Network (IP-CAN) session. In a roaming scenario withlocal breakout of traffic, there may be two PCRFs associated with a UE501's IP-CAN session, a Home PCRF (H-PCRF) within an HPLMN and a VisitedPCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). ThePCRF 526 may be communicatively coupled to the application server 530via the P-GW 523. The application server 530 may signal the PCRF 526 toindicate a new service flow and select the appropriate QoS and chargingparameters. The PCRF 526 may provision this rule into a PCEF (not shown)with the appropriate TFT and QCI, which commences the QoS and chargingas specified by the application server 530. The Gx reference pointbetween the PCRF 526 and the P-GW 523 may allow for the transfer of QoSpolicy and charging rules from the PCRF 526 to PCEF in the P-GW 523. AnRx reference point may reside between the PDN 530 (or “AF 530”) and thePCRF 526.

FIG. 6 illustrates an architecture of a system 600 including a second CN620 in accordance with various embodiments. The system 600 is shown toinclude a UE 601, which may be the same or similar to the UEs 401 and UE501 discussed previously; a (R)AN 610, which may be the same or similarto the RAN 410 and RAN 510 discussed previously, and which may includeRAN nodes 411 discussed previously; and a DN 603, which may be, forexample, operator services, Internet access or 3rd party services; and a5GC 620. The 5GC 620 may include an AUSF 622; an AMF 621; a SMF 624; aNEF 623; a PCF 626; a NRF 625; a UDM 627; an AF 628; a UPF 602; and aNSSF 629.

The UPF 602 may act as an anchor point for intra-RAT and inter-RATmobility, an external PDU session point of interconnect to DN 603, and abranching point to support multi-homed PDU session. The UPF 602 may alsoperform packet routing and forwarding, perform packet inspection,enforce the user plane part of policy rules, lawfully intercept packets(UP collection), perform traffic usage reporting, perform QoS handlingfor a user plane (e.g., packet filtering, gating, UL/DL rateenforcement), perform Uplink Traffic verification (e.g., SDF to QoS flowmapping), transport level packet marking in the uplink and downlink, andperform downlink packet buffering and downlink data notificationtriggering. UPF 602 may include an uplink classifier to support routingtraffic flows to a data network. The DN 603 may represent variousnetwork operator services, Internet access, or third party services. DN603 may include, or be similar to, application server 430 discussedpreviously. The UPF 602 may interact with the SMF 624 via an N4reference point between the SMF 624 and the UPF 602.

The AUSF 622 may store data for authentication of UE 601 and handleauthentication-related functionality. The AUSF 622 may facilitate acommon authentication framework for various access types. The AUSF 622may communicate with the AMF 621 via an N12 reference point between theAMF 621 and the AUSF 622; and may communicate with the UDM 627 via anN13 reference point between the UDM 627 and the AUSF 622. Additionally,the AUSF 622 may exhibit an Nausf service-based interface.

The AMF 621 may be responsible for registration management (e.g., forregistering UE 601, etc.), connection management, reachabilitymanagement, mobility management, and lawful interception of AMF-relatedevents, and access authentication and authorization. The AMF 621 may bea termination point for the an N11 reference point between the AMF 621and the SMF 624. The AMF 621 may provide transport for SM messagesbetween the UE 601 and the SMF 624, and act as a transparent pro12 forrouting SM messages. AMF 621 may also provide transport for SMS messagesbetween UE 601 and an SMSF (not shown by FIG. 6 ). AMF 621 may act asSEAF, which may include interaction with the AUSF 622 and the UE 601,receipt of an intermediate key that was established as a result of theUE 601 authentication process. Where USIM based authentication is used,the AMF 621 may retrieve the security material from the AUSF 622. AMF621 may also include a SCM function, which receives a key from the SEAthat it uses to derive access-network specific keys. Furthermore, AMF621 may be a termination point of a RAN CP interface, which may includeor be an N2 reference point between the (R)AN 610 and the AMF 621; andthe AMF 621 may be a termination point of NAS (N1) signalling, andperform NAS ciphering and integrity protection.

AMF 621 may also support NAS signalling with a UE 601 over an N3 IWFinterface. The N3IWF may be used to provide access to untrustedentities. N3IWF may be a termination point for the N2 interface betweenthe (R)AN 610 and the AMF 621 for the control plane, and may be atermination point for the N3 reference point between the (R)AN 610 andthe UPF 602 for the user plane. As such, the AMF 621 may handle N2signalling from the SMF 624 and the AMF 621 for PDU sessions and QoS,encapsulate/de-encapsulate packets for IPSec and N3 tunnelling, mark N3user-plane packets in the uplink, and enforce QoS corresponding to N3packet marking taking into account QoS requirements associated with suchmarking received over N2. N3IWF may also relay uplink and downlinkcontrol-plane NAS signalling between the UE 601 and AMF 621 via an N1reference point between the UE 601 and the AMF 621, and relay uplink anddownlink user-plane packets between the UE 601 and UPF 602. The N3IWFalso provides mechanisms for IPsec tunnel establishment with the UE 601.The AMF 621 may exhibit an Namf service-based interface, and may be atermination point for an N14 reference point between two AMFs 621 and anN17 reference point between the AMF 621 and a 5G-EIR (not shown by FIG.6 ).

The UE 601 may need to register with the AMF 621 in order to receivenetwork services. RM is used to register or deregister the UE 601 withthe network (e.g., AMF 621), and establish a UE context in the network(e.g., AMF 621). The UE 601 may operate in an RM-REGISTERED state or anRM-DEREGISTERED state. In the RM-DEREGISTERED state, the UE 601 is notregistered with the network, and the UE context in AMF 621 holds novalid location or routing information for the UE 601 so the UE 601 isnot reachable by the AMF 621. In the RM-REGISTERED state, the UE 601 isregistered with the network, and the UE context in AMF 621 may hold avalid location or routing information for the UE 601 so the UE 601 isreachable by the AMF 621. In the RM-REGISTERED state, the UE 601 mayperform mobility Registration Update procedures, perform periodicRegistration Update procedures triggered by expiration of the periodicupdate timer (e.g., to notify the network that the UE 601 is stillactive), and perform a Registration Update procedure to update UEcapability information or to re-negotiate protocol parameters with thenetwork, among others.

The AMF 621 may store one or more RM contexts for the UE 601, where eachRM context is associated with a specific access to the network. The RMcontext may be a data structure, database object, etc. that indicates orstores, inter alia, a registration state per access type and theperiodic update timer. The AMF 621 may also store a 5GC MM context thatmay be the same or similar to the (E)MM context discussed previously. Invarious embodiments, the AMF 621 may store a CE mode B Restrictionparameter of the UE 601 in an associated MM context or RM context. TheAMF 621 may also derive the value, when needed, from the UE's usagesetting parameter already stored in the UE context (and/or MM/RMcontext).

CM may be used to establish and release a signaling connection betweenthe UE 601 and the AMF 621 over the N1 interface. The signalingconnection is used to enable NAS signaling exchange between the UE 601and the CN 620, and comprises both the signaling connection between theUE and the AN (e.g., RRC connection or UE-N3IWF connection for non-3GPPaccess) and the N2 connection for the UE 601 between the AN (e.g., RAN610) and the AMF 621. The UE 601 may operate in one of two CM states,CM-IDLE mode or CM-CONNECTED mode. When the UE 601 is operating in theCM-IDLE state/mode, the UE 601 may have no NAS signaling connectionestablished with the AMF 621 over the N1 interface, and there may be(R)AN 610 signaling connection (e.g., N2 and/or N3 connections) for theUE 601. When the UE 601 is operating in the CM-CONNECTED state/mode, theUE 601 may have an established NAS signaling connection with the AMF 621over the N1 interface, and there may be a (R)AN 610 signaling connection(e.g., N2 and/or N3 connections) for the UE 601. Establishment of an N2connection between the (R)AN 610 and the AMF 621 may cause the UE 601 totransition from CM-IDLE mode to CM-CONNECTED mode, and the UE 601 maytransition from the CM-CONNECTED mode to the CM-IDLE mode when N2signaling between the (R)AN 610 and the AMF 621 is released.

The SMF 624 may be responsible for SM (e.g., session establishment,modify and release, including tunnel maintain between UPF and AN node);UE IP address allocation and management (including optionalauthorization); selection and control of UP function; configuringtraffic steering at UPF to route traffic to proper destination;termination of interfaces toward policy control functions; controllingpart of policy enforcement and QoS; lawful intercept (for SM events andinterface to LI system); termination of SM parts of NAS messages;downlink data notification; initiating AN specific SM information, sentvia AMF over N2 to AN; and determining SSC mode of a session. SM mayrefer to management of a PDU session, and a PDU session or “session” mayrefer to a PDU connectivity service that provides or enables theexchange of PDUs between a UE 601 and a data network (DN) 603 identifiedby a Data Network Name (DNN). PDU sessions may be established upon UE601 request, modified upon UE 601 and 5GC 620 request, and released uponUE 601 and 5GC 620 request using NAS SM signaling exchanged over the N1reference point between the UE 601 and the SMF 624. Upon request from anapplication server, the 5GC 620 may trigger a specific application inthe UE 601. In response to receipt of the trigger message, the UE 601may pass the trigger message (or relevant parts/information of thetrigger message) to one or more identified applications in the UE 601.The identified application(s) in the UE 601 may establish a PDU sessionto a specific DNN. The SMF 624 may check whether the UE 601 requests arecompliant with user subscription information associated with the UE 601.In this regard, the SMF 624 may retrieve and/or request to receiveupdate notifications on SMF 624 level subscription data from the UDM627.

The SMF 624 may include the following roaming functionality: handlinglocal enforcement to apply QoS SLAB (VPLMN); charging data collectionand charging interface (VPLMN); lawful intercept (in VPLMN for SM eventsand interface to LI system); and support for interaction with externalDN for transport of signalling for PDU sessionauthorization/authentication by external DN. An N16 reference pointbetween two SMFs 624 may be included in the system 600, which may bebetween another SMF 624 in a visited network and the SMF 624 in the homenetwork in roaming scenarios. Additionally, the SMF 624 may exhibit theNsmf service-based interface.

The NEF 623 may provide means for securely exposing the services andcapabilities provided by 3GPP network functions for third party,internal exposure/re-exposure, Application Functions (e.g., AF 628),edge computing or fog computing systems, etc. In such embodiments, theNEF 623 may authenticate, authorize, and/or throttle the AFs. NEF 623may also translate information exchanged with the AF 628 and informationexchanged with internal network functions. For example, the NEF 623 maytranslate between an AF-Service-Identifier and an internal 5GCinformation. NEF 623 may also receive information from other networkfunctions (NFs) based on exposed capabilities of other networkfunctions. This information may be stored at the NEF 623 as structureddata, or at a data storage NF using standardized interfaces. The storedinformation can then be re-exposed by the NEF 623 to other NFs and AFs,and/or used for other purposes such as analytics. Additionally, the NEF623 may exhibit an Nnef service-based interface.

The NRF 625 may support service discovery functions, receive NFdiscovery requests from NF instances, and provide the information of thediscovered NF instances to the NF instances. NRF 625 also maintainsinformation of available NF instances and their supported services. Asused herein, the terms “instantiate,” “instantiation,” and the like mayrefer to the creation of an instance, and an “instance” may refer to aconcrete occurrence of an object, which may occur, for example, duringexecution of program code. Additionally, the NRF 625 may exhibit theNnrf service-based interface.

The PCF 626 may provide policy rules to control plane function(s) toenforce them, and may also support unified policy framework to governnetwork behaviour. The PCF 626 may also implement an FE to accesssubscription information relevant for policy decisions in a UDR of theUDM 627. The PCF 626 may communicate with the AMF 621 via an N15reference point between the PCF 626 and the AMF 621, which may include aPCF 626 in a visited network and the AMF 621 in case of roamingscenarios. The PCF 626 may communicate with the AF 628 via an N5reference point between the PCF 626 and the AF 628; and with the SMF 624via an N7 reference point between the PCF 626 and the SMF 624. Thesystem 600 and/or CN 620 may also include an N24 reference point betweenthe PCF 626 (in the home network) and a PCF 626 in a visited network.Additionally, the PCF 626 may exhibit an Npcf service-based interface.

The UDM 627 may handle subscription-related information to support thenetwork entities' handling of communication sessions, and may storesubscription data of UE 601. For example, subscription data may becommunicated between the UDM 627 and the AMF 621 via an N8 referencepoint between the UDM 627 and the AMF. The UDM 627 may include twoparts, an application FE and a UDR (the FE and UDR are not shown by FIG.6 ). The UDR may store subscription data and policy data for the UDM 627and the PCF 626, and/or structured data for exposure and applicationdata (including PFDs for application detection, application requestinformation for multiple UEs 601) for the NEF 623. The Nudrservice-based interface may be exhibited by the UDR 221 to allow the UDM627, PCF 626, and NEF 623 to access a particular set of the stored data,as well as to read, update (e.g., add, modify), delete, and subscribe tonotification of relevant data changes in the UDR. The UDM may include aUDM-FE, which is in charge of processing credentials, locationmanagement, subscription management and so on. Several different frontends may serve the same user in different transactions. The UDM-FEaccesses subscription information stored in the UDR and performsauthentication credential processing, user identification handling,access authorization, registration/mobility management, and subscriptionmanagement. The UDR may interact with the SMF 624 via an N10 referencepoint between the UDM 627 and the SMF 624. UDM 627 may also support SMSmanagement, wherein an SMS-FE implements the similar application logicas discussed previously. Additionally, the UDM 627 may exhibit the Nudmservice-based interface.

The AF 628 may provide application influence on traffic routing, provideaccess to the NCE, and interact with the policy framework for policycontrol. The NCE may be a mechanism that allows the 5GC 620 and AF 628to provide information to each other via NEF 623, which may be used foredge computing implementations. In such implementations, the networkoperator and third party services may be hosted close to the UE 601access point of attachment to achieve an efficient service deliverythrough the reduced end-to-end latency and load on the transportnetwork. For edge computing implementations, the 5GC may select a UPF602 close to the UE 601 and execute traffic steering from the UPF 602 toDN 603 via the N6 interface. This may be based on the UE subscriptiondata, UE location, and information provided by the AF 628. In this way,the AF 628 may influence UPF (re)selection and traffic routing. Based onoperator deployment, when AF 628 is considered to be a trusted entity,the network operator may permit AF 628 to interact directly withrelevant NFs. Additionally, the AF 628 may exhibit an Naf service-basedinterface.

The NSSF 629 may select a set of network slice instances serving the UE601. The NSSF 629 may also determine allowed NSSAI and the mapping tothe subscribed S-NSSAIs, if needed. The NSSF 629 may also determine theAMF set to be used to serve the UE 601, or a list of candidate AMF(s)621 based on a suitable configuration and possibly by querying the NRF625. The selection of a set of network slice instances for the UE 601may be triggered by the AMF 621 with which the UE 601 is registered byinteracting with the NSSF 629, which may lead to a change of AMF 621.The NSSF 629 may interact with the AMF 621 via an N22 reference pointbetween AMF 621 and NSSF 629; and may communicate with another NSSF 629in a visited network via an N31 reference point (not shown by FIG. 6 ).Additionally, the NSSF 629 may exhibit an Nnssf service-based interface.

As discussed previously, the CN 620 may include an SMSF, which may beresponsible for SMS subscription checking and verification, and relayingSM messages to/from the UE 601 to/from other entities, such as anSMS-GMSC/IWMSC/SMS-router. The SMS may also interact with AMF 621 andUDM 627 for a notification procedure that the UE 601 is available forSMS transfer (e.g., set a UE not reachable flag, and notifying UDM 627when UE 601 is available for SMS).

The CN 120 may also include other elements that are not shown by FIG. 6, such as a Data Storage system/architecture, a 5G-EIR, a SEPP, and thelike. The Data Storage system may include a SDSF, an UDSF, and/or thelike. Any NF may store and retrieve unstructured data into/from the UDSF(e.g., UE contexts), via N18 reference point between any NF and the UDSF(not shown by FIG. 6 ). Individual NFs may share a UDSF for storingtheir respective unstructured data or individual NFs may each have theirown UDSF located at or near the individual NFs. Additionally, the UDSFmay exhibit an Nudsf service-based interface (not shown by FIG. 6 ). The5G-EIR may be an NF that checks the status of PEI for determiningwhether particular equipment/entities are blacklisted from the network;and the SEPP may be a non-transparent pro12 that performs topologyhiding, message filtering, and policing on inter-PLMN control planeinterfaces.

Additionally, there may be many more reference points and/orservice-based interfaces between the NF services in the NFs; however,these interfaces and reference points have been omitted from FIG. 6 forclarity. In one example, the CN 620 may include an Nx interface, whichis an inter-CN interface between the MME (e.g., MME 521) and the AMF 621in order to enable interworking between CN 620 and CN 520. Other exampleinterfaces/reference points may include an N5g-EIR service-basedinterface exhibited by a 5G-EIR, an N27 reference point between the NRFin the visited network and the NRF in the home network; and an N31reference point between the NSSF in the visited network and the NSSF inthe home network.

FIG. 7 illustrates an example of infrastructure equipment 700 inaccordance with various embodiments. The infrastructure equipment 700(or “system 700”) may be implemented as a base station, radio head, RANnode such as the RAN nodes 411 and/or AP 406 shown and describedpreviously, application server(s) 430, and/or any other element/devicediscussed herein. In other examples, the system 700 could be implementedin or by a UE.

The system 700 includes application circuitry 705, baseband circuitry710, one or more radio front end modules (RFEMs) 715, memory circuitry720, power management integrated circuitry (PMIC) 725, power teecircuitry 730, network controller circuitry 735, network interfaceconnector 740, satellite positioning circuitry 745, and user interface750. In some embodiments, the device 700 may include additional elementssuch as, for example, memory/storage, display, camera, sensor, orinput/output (I/O) interface. In other embodiments, the componentsdescribed below may be included in more than one device. For example,said circuitries may be separately included in more than one device forCRAN, vBBU, or other like implementations.

Application circuitry 705 includes circuitry such as, but not limited toone or more processors (or processor cores), cache memory, and one ormore of low drop-out voltage regulators (LDOs), interrupt controllers,serial interfaces such as SPI, I²C or universal programmable serialinterface module, real time clock (RTC), timer-counters includinginterval and watchdog timers, general purpose input/output (I/O or IO),memory card controllers such as Secure Digital (SD) MultiMediaCard (MMC)or similar, Universal Serial Bus (USB) interfaces, Mobile IndustryProcessor Interface (MIPI) interfaces and Joint Test Access Group (JTAG)test access ports. The processors (or cores) of the applicationcircuitry 705 may be coupled with or may include memory/storage elementsand may be configured to execute instructions stored in thememory/storage to enable various applications or operating systems torun on the system 700. In some implementations, the memory/storageelements may be on-chip memory circuitry, which may include any suitablevolatile and/or non-volatile memory, such as DRAM, SRAM, EPROM, EEPROM,Flash memory, solid-state memory, and/or any other type of memory devicetechnology, such as those discussed herein.

The processor(s) of application circuitry 705 may include, for example,one or more processor cores (CPUs), one or more application processors,one or more graphics processing units (GPUs), one or more reducedinstruction set computing (RISC) processors, one or more Acorn RISCMachine (ARM) processors, one or more complex instruction set computing(CISC) processors, one or more digital signal processors (DSP), one ormore FPGAs, one or more PLDs, one or more ASICs, one or moremicroprocessors or controllers, or any suitable combination thereof. Insome embodiments, the application circuitry 705 may comprise, or may be,a special-purpose processor/controller to operate according to thevarious embodiments herein. As examples, the processor(s) of applicationcircuitry 705 may include one or more Intel Pentium®, Core®, or Xeon®processor(s); Advanced Micro Devices (AMD) Ryzen® processor(s),Accelerated Processing Units (APUs), or Epyc® processors; ARM-basedprocessor(s) licensed from ARM Holdings, Ltd. such as the ARM Cortex-Afamily of processors and the ThunderX2® provided by Cavium™, Inc.; aMIPS-based design from MIPS Technologies, Inc. such as MIPS WarriorP-class processors; and/or the like. In some embodiments, the system 700may not utilize application circuitry 705, and instead may include aspecial-purpose processor/controller to process IP data received from anEPC or 5GC, for example.

In some implementations, the application circuitry 705 may include oneor more hardware accelerators, which may be microprocessors,programmable processing devices, or the like. The one or more hardwareaccelerators may include, for example, computer vision (CV) and/or deeplearning (DL) accelerators. As examples, the programmable processingdevices may be one or more a field-programmable devices (FPDs) such asfield-programmable gate arrays (FPGAs) and the like; programmable logicdevices (PLDs) such as complex PLDs (CPLDs), high-capacity PLDs(HCPLDs), and the like; ASICs such as structured ASICs and the like;programmable SoCs (PSoCs); and the like. In such implementations, thecircuitry of application circuitry 705 may comprise logic blocks orlogic fabric, and other interconnected resources that may be programmedto perform various functions, such as the procedures, methods,functions, etc. of the various embodiments discussed herein. In suchembodiments, the circuitry of application circuitry 705 may includememory cells (e.g., erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), flashmemory, static memory (e.g., static random access memory (SRAM),anti-fuses, etc.)) used to store logic blocks, logic fabric, data, etc.in look-up-tables (LUTs) and the like.

The baseband circuitry 710 may be implemented, for example, as asolder-down substrate including one or more integrated circuits, asingle packaged integrated circuit soldered to a main circuit board or amulti-chip module containing two or more integrated circuits. Thevarious hardware electronic elements of baseband circuitry 710 arediscussed infra with regard to FIG. 9 .

User interface circuitry 750 may include one or more user interfacesdesigned to enable user interaction with the system 700 or peripheralcomponent interfaces designed to enable peripheral component interactionwith the system 700. User interfaces may include, but are not limitedto, one or more physical or virtual buttons (e.g., a reset button), oneor more indicators (e.g., light emitting diodes (LEDs)), a physicalkeyboard or keypad, a mouse, a touchpad, a touchscreen, speakers orother audio emitting devices, microphones, a printer, a scanner, aheadset, a display screen or display device, etc. Peripheral componentinterfaces may include, but are not limited to, a nonvolatile memoryport, a universal serial bus (USB) port, an audio jack, a power supplyinterface, etc.

The radio front end modules (RFEMs) 715 may comprise a millimeter wave(mmWave) RFEM and one or more sub-mmWave radio frequency integratedcircuits (RFICs). In some implementations, the one or more sub-mmWaveRFICs may be physically separated from the mmWave RFEM. The RFICs mayinclude connections to one or more antennas or antenna arrays (see e.g.,antenna array 911 of FIG. 9 infra), and the RFEM may be connected tomultiple antennas. In alternative implementations, both mmWave andsub-mmWave radio functions may be implemented in the same physical RFEM715, which incorporates both mmWave antennas and sub-mmWave.

The memory circuitry 720 may include one or more of volatile memoryincluding dynamic random access memory (DRAM) and/or synchronous dynamicrandom access memory (SDRAM), and nonvolatile memory (NVM) includinghigh-speed electrically erasable memory (commonly referred to as Flashmemory), phase change random access memory (PRAM), magnetoresistiverandom access memory (MRAM), etc., and may incorporate thethree-dimensional (3D) cross-point (XPOINT) memories from Intel® andMicron®. Memory circuitry 720 may be implemented as one or more ofsolder down packaged integrated circuits, socketed memory modules andplug-in memory cards.

The PMIC 725 may include voltage regulators, surge protectors, poweralarm detection circuitry, and one or more backup power sources such asa battery or capacitor. The power alarm detection circuitry may detectone or more of brown out (under-voltage) and surge (over-voltage)conditions. The power tee circuitry 730 may provide for electrical powerdrawn from a network cable to provide both power supply and dataconnectivity to the infrastructure equipment 700 using a single cable.

The network controller circuitry 735 may provide connectivity to anetwork using a standard network interface protocol such as Ethernet,Ethernet over GRE Tunnels, Ethernet over Multiprotocol Label Switching(MPLS), or some other suitable protocol. Network connectivity may beprovided to/from the infrastructure equipment 700 via network interfaceconnector 740 using a physical connection, which may be electrical(commonly referred to as a “copper interconnect”), optical, or wireless.The network controller circuitry 735 may include one or more dedicatedprocessors and/or FPGAs to communicate using one or more of theaforementioned protocols. In some implementations, the networkcontroller circuitry 735 may include multiple controllers to provideconnectivity to other networks using the same or different protocols.

The positioning circuitry 745 includes circuitry to receive and decodesignals transmitted/broadcasted by a positioning network of a globalnavigation satellite system (GNSS). Examples of navigation satelliteconstellations (or GNSS) include United States' Global PositioningSystem (GPS), Russia's Global Navigation System (GLONASS), the EuropeanUnion's Galileo system, China's BeiDou Navigation Satellite System, aregional navigation system or GNSS augmentation system (e.g., Navigationwith Indian Constellation (NAVIC), Japan's Quasi-Zenith Satellite System(QZSS), France's Doppler Orbitography and Radio-positioning Integratedby Satellite (DORIS), etc.), or the like. The positioning circuitry 745comprises various hardware elements (e.g., including hardware devicessuch as switches, filters, amplifiers, antenna elements, and the like tofacilitate OTA communications) to communicate with components of apositioning network, such as navigation satellite constellation nodes.In some embodiments, the positioning circuitry 745 may include aMicro-Technology for Positioning, Navigation, and Timing (Micro-PNT) ICthat uses a master timing clock to perform position tracking/estimationwithout GNSS assistance. The positioning circuitry 745 may also be partof, or interact with, the baseband circuitry 710 and/or RFEMs 715 tocommunicate with the nodes and components of the positioning network.The positioning circuitry 745 may also provide position data and/or timedata to the application circuitry 705, which may use the data tosynchronize operations with various infrastructure (e.g., RAN nodes 411,etc.), or the like.

The components shown by FIG. 7 may communicate with one another usinginterface circuitry, which may include any number of bus and/orinterconnect (IX) technologies such as industry standard architecture(ISA), extended ISA (EISA), peripheral component interconnect (PCI),peripheral component interconnect extended (PCIx), PCI express (PCIe),or any number of other technologies. The bus/IX may be a proprietarybus, for example, used in a SoC based system. Other bus/IX systems maybe included, such as an I²C interface, an SPI interface, point to pointinterfaces, and a power bus, among others.

FIG. 8 illustrates an example of a platform 800 (or “device 800”) inaccordance with various embodiments. In embodiments, the computerplatform 800 may be suitable for use as UEs 401, 402, 501, applicationservers 430, and/or any other element/device discussed herein. Theplatform 800 may include any combinations of the components shown in theexample. The components of platform 800 may be implemented as integratedcircuits (ICs), portions thereof, discrete electronic devices, or othermodules, logic, hardware, software, firmware, or a combination thereofadapted in the computer platform 800, or as components otherwiseincorporated within a chassis of a larger system. The block diagram ofFIG. 8 is intended to show a high level view of components of thecomputer platform 800. However, some of the components shown may beomitted, additional components may be present, and different arrangementof the components shown may occur in other implementations.

Application circuitry 805 includes circuitry such as, but not limited toone or more processors (or processor cores), cache memory, and one ormore of LDOs, interrupt controllers, serial interfaces such as SPI, I²Cor universal programmable serial interface module, RTC, timer-countersincluding interval and watchdog timers, general purpose I/O, memory cardcontrollers such as SD MMC or similar, USB interfaces, MIPI interfaces,and JTAG test access ports. The processors (or cores) of the applicationcircuitry 805 may be coupled with or may include memory/storage elementsand may be configured to execute instructions stored in thememory/storage to enable various applications or operating systems torun on the system 800. In some implementations, the memory/storageelements may be on-chip memory circuitry, which may include any suitablevolatile and/or non-volatile memory, such as DRAM, SRAM, EPROM, EEPROM,Flash memory, solid-state memory, and/or any other type of memory devicetechnology, such as those discussed herein.

The processor(s) of application circuitry 705 may include, for example,one or more processor cores, one or more application processors, one ormore GPUs, one or more RISC processors, one or more ARM processors, oneor more CISC processors, one or more DSP, one or more FPGAs, one or morePLDs, one or more ASICs, one or more microprocessors or controllers, amultithreaded processor, an ultra-low voltage processor, an embeddedprocessor, some other known processing element, or any suitablecombination thereof. In some embodiments, the application circuitry 705may comprise, or may be, a special-purpose processor/controller tooperate according to the various embodiments herein.

As examples, the processor(s) of application circuitry 805 may includean Intel® Architecture Core™ based processor, such as a Quark™, anAtom™, an i3, an i5, an i7, or an MCU-class processor, or another suchprocessor available from Intel® Corporation, Santa Clara, Calif. Theprocessors of the application circuitry 805 may also be one or more ofAdvanced Micro Devices (AMD) Ryzen® processor(s) or AcceleratedProcessing Units (APUs); A5-A9 processor(s) from Apple® Inc.,Snapdragon™ processor(s) from Qualcomm® Technologies, Inc., TexasInstruments, Inc.® Open Multimedia Applications Platform (OMAP)™processor(s); a MIPS-based design from MIPS Technologies, Inc. such asMIPS Warrior M-class, Warrior I-class, and Warrior P-class processors;an ARM-based design licensed from ARM Holdings, Ltd., such as the ARMCortex-A, Cortex-R, and Cortex-M family of processors; or the like. Insome implementations, the application circuitry 805 may be a part of asystem on a chip (SoC) in which the application circuitry 805 and othercomponents are formed into a single integrated circuit, or a singlepackage, such as the Edison™ or Galileo™ SoC boards from Intel®Corporation.

Additionally or alternatively, application circuitry 805 may includecircuitry such as, but not limited to, one or more a field-programmabledevices (FPDs) such as FPGAs and the like; programmable logic devices(PLDs) such as complex PLDs (CPLDs), high-capacity PLDs (HCPLDs), andthe like; ASICs such as structured ASICs and the like; programmable SoCs(PSoCs); and the like. In such embodiments, the circuitry of applicationcircuitry 805 may comprise logic blocks or logic fabric, and otherinterconnected resources that may be programmed to perform variousfunctions, such as the procedures, methods, functions, etc. of thevarious embodiments discussed herein. In such embodiments, the circuitryof application circuitry 805 may include memory cells (e.g., erasableprogrammable read-only memory (EPROM), electrically erasableprogrammable read-only memory (EEPROM), flash memory, static memory(e.g., static random access memory (SRAM), anti-fuses, etc.)) used tostore logic blocks, logic fabric, data, etc. in look-up tables (LUTs)and the like.

The baseband circuitry 810 may be implemented, for example, as asolder-down substrate including one or more integrated circuits, asingle packaged integrated circuit soldered to a main circuit board or amulti-chip module containing two or more integrated circuits. Thevarious hardware electronic elements of baseband circuitry 810 arediscussed infra with regard to FIG. 9 .

The RFEMs 815 may comprise a millimeter wave (mmWave) RFEM and one ormore sub-mmWave radio frequency integrated circuits (RFICs). In someimplementations, the one or more sub-mmWave RFICs may be physicallyseparated from the mmWave RFEM. The RFICs may include connections to oneor more antennas or antenna arrays (see e.g., antenna array 911 of FIG.9 infra), and the RFEM may be connected to multiple antennas. Inalternative implementations, both mmWave and sub-mmWave radio functionsmay be implemented in the same physical RFEM 815, which incorporatesboth mmWave antennas and sub-mmWave.

The memory circuitry 820 may include any number and type of memorydevices used to provide for a given amount of system memory. Asexamples, the memory circuitry 820 may include one or more of volatilememory including random access memory (RAM), dynamic RAM (DRAM) and/orsynchronous dynamic RAM (SDRAM), and nonvolatile memory (NVM) includinghigh-speed electrically erasable memory (commonly referred to as Flashmemory), phase change random access memory (PRAM), magnetoresistiverandom access memory (MRAM), etc. The memory circuitry 820 may bedeveloped in accordance with a Joint Electron Devices EngineeringCouncil (JEDEC) low power double data rate (LPDDR)-based design, such asLPDDR2, LPDDR3, LPDDR4, or the like. Memory circuitry 820 may beimplemented as one or more of solder down packaged integrated circuits,single die package (SDP), dual die package (DDP) or quad die package(Q17P), socketed memory modules, dual inline memory modules (DIMMs)including microDIMMs or MiniDIMMs, and/or soldered onto a motherboardvia a ball grid array (BGA). In low power implementations, the memorycircuitry 820 may be on-die memory or registers associated with theapplication circuitry 805. To provide for persistent storage ofinformation such as data, applications, operating systems and so forth,memory circuitry 820 may include one or more mass storage devices, whichmay include, inter alia, a solid state disk drive (SSDD), hard diskdrive (HDD), a micro HDD, resistance change memories, phase changememories, holographic memories, or chemical memories, among others. Forexample, the computer platform 800 may incorporate the three-dimensional(3D) cross-point (XPOINT) memories from Intel® and Micron®.

Removable memory circuitry 823 may include devices, circuitry,enclosures/housings, ports or receptacles, etc. used to couple portabledata storage devices with the platform 800. These portable data storagedevices may be used for mass storage purposes, and may include, forexample, flash memory cards (e.g., Secure Digital (SD) cards, microSDcards, xD picture cards, and the like), and USB flash drives, opticaldiscs, external HDDs, and the like.

The platform 800 may also include interface circuitry (not shown) thatis used to connect external devices with the platform 800. The externaldevices connected to the platform 800 via the interface circuitryinclude sensor circuitry 821 and electro-mechanical components (EMCs)822, as well as removable memory devices coupled to removable memorycircuitry 823.

The sensor circuitry 821 include devices, modules, or subsystems whosepurpose is to detect events or changes in its environment and send theinformation (sensor data) about the detected events to some other adevice, module, subsystem, etc. Examples of such sensors include, interalia, inertia measurement units (IMUs) comprising accelerometers,gyroscopes, and/or magnetometers; microelectromechanical systems (MEMS)or nanoelectromechanical systems (NEMS) comprising 3-axisaccelerometers, 3-axis gyroscopes, and/or magnetometers; level sensors;flow sensors; temperature sensors (e.g., thermistors); pressure sensors;barometric pressure sensors; gravimeters; altimeters; image capturedevices (e.g., cameras or lensless apertures); light detection andranging (LiDAR) sensors; proximity sensors (e.g., infrared radiationdetector and the like), depth sensors, ambient light sensors, ultrasonictransceivers; microphones or other like audio capture devices; etc.

EMCs 822 include devices, modules, or subsystems whose purpose is toenable platform 800 to change its state, position, and/or orientation,or move or control a mechanism or (sub)system. Additionally, EMCs 822may be configured to generate and send messages/signalling to othercomponents of the platform 800 to indicate a current state of the EMCs822. Examples of the EMCs 822 include one or more power switches, relaysincluding electromechanical relays (EMRs) and/or solid state relays(SSRs), actuators (e.g., valve actuators, etc.), an audible soundgenerator, a visual warning device, motors (e.g., DC motors, steppermotors, etc.), wheels, thrusters, propellers, claws, clamps, hooks,and/or other like electro-mechanical components. In embodiments,platform 800 is configured to operate one or more EMCs 822 based on oneor more captured events and/or instructions or control signals receivedfrom a service provider and/or various clients.

In some implementations, the interface circuitry may connect theplatform 800 with positioning circuitry 845. The positioning circuitry845 includes circuitry to receive and decode signalstransmitted/broadcasted by a positioning network of a GNSS. Examples ofnavigation satellite constellations (or GNSS) include United States'GPS, Russia's GLONASS, the European Union's Galileo system, China'sBeiDou Navigation Satellite System, a regional navigation system or GNSSaugmentation system (e.g., NAVIC), Japan's QZSS, France's DORIS, etc.),or the like. The positioning circuitry 845 comprises various hardwareelements (e.g., including hardware devices such as switches, filters,amplifiers, antenna elements, and the like to facilitate OTAcommunications) to communicate with components of a positioning network,such as navigation satellite constellation nodes. In some embodiments,the positioning circuitry 845 may include a Micro-PNT IC that uses amaster timing clock to perform position tracking/estimation without GNSSassistance. The positioning circuitry 845 may also be part of, orinteract with, the baseband circuitry 710 and/or RFEMs 815 tocommunicate with the nodes and components of the positioning network.The positioning circuitry 845 may also provide position data and/or timedata to the application circuitry 805, which may use the data tosynchronize operations with various infrastructure (e.g., radio basestations), for turn-by-turn navigation applications, or the like

In some implementations, the interface circuitry may connect theplatform 800 with Near-Field Communication (NFC) circuitry 840. NFCcircuitry 840 is configured to provide contactless, short-rangecommunications based on radio frequency identification (RFID) standards,wherein magnetic field induction is used to enable communication betweenNFC circuitry 840 and NFC-enabled devices external to the platform 800(e.g., an “NFC touchpoint”). NFC circuitry 840 comprises an NFCcontroller coupled with an antenna element and a processor coupled withthe NFC controller. The NFC controller may be a chip/IC providing NFCfunctionalities to the NFC circuitry 840 by executing NFC controllerfirmware and an NFC stack. The NFC stack may be executed by theprocessor to control the NFC controller, and the NFC controller firmwaremay be executed by the NFC controller to control the antenna element toemit short-range RF signals. The RF signals may power a passive NFC tag(e.g., a microchip embedded in a sticker or wristband) to transmitstored data to the NFC circuitry 840, or initiate data transfer betweenthe NFC circuitry 840 and another active NFC device (e.g., a smartphoneor an NFC-enabled POS terminal) that is proximate to the platform 800.

The driver circuitry 846 may include software and hardware elements thatoperate to control particular devices that are embedded in the platform800, attached to the platform 800, or otherwise communicatively coupledwith the platform 800. The driver circuitry 846 may include individualdrivers allowing other components of the platform 800 to interact withor control various input/output (I/O) devices that may be presentwithin, or connected to, the platform 800. For example, driver circuitry846 may include a display driver to control and allow access to adisplay device, a touchscreen driver to control and allow access to atouchscreen interface of the platform 800, sensor drivers to obtainsensor readings of sensor circuitry 821 and control and allow access tosensor circuitry 821, EMC drivers to obtain actuator positions of theEMCs 822 and/or control and allow access to the EMCs 822, a cameradriver to control and allow access to an embedded image capture device,audio drivers to control and allow access to one or more audio devices.

The power management integrated circuitry (PMIC) 825 (also referred toas “power management circuitry 825”) may manage power provided tovarious components of the platform 800. In particular, with respect tothe baseband circuitry 810, the PMIC 825 may control power-sourceselection, voltage scaling, battery charging, or DC-to-DC conversion.The PMIC 825 may often be included when the platform 800 is capable ofbeing powered by a battery 830, for example, when the device is includedin a UE 401, 402, 501.

In some embodiments, the PMIC 825 may control, or otherwise be part of,various power saving mechanisms of the platform 800. For example, if theplatform 800 is in an RRC_Connected state, where it is still connectedto the RAN node as it expects to receive traffic shortly, then it mayenter a state known as Discontinuous Reception Mode (DRX) after a periodof inactivity. During this state, the platform 800 may power down forbrief intervals of time and thus save power. If there is no data trafficactivity for an extended period of time, then the platform 800 maytransition off to an RRC_Idle state, where it disconnects from thenetwork and does not perform operations such as channel qualityfeedback, handover, etc. The platform 800 goes into a very low powerstate and it performs paging where again it periodically wakes up tolisten to the network and then powers down again. The platform 800 maynot receive data in this state; in order to receive data, it musttransition back to RRC_Connected state. An additional power saving modemay allow a device to be unavailable to the network for periods longerthan a paging interval (ranging from seconds to a few hours). Duringthis time, the device is totally unreachable to the network and maypower down completely. Any data sent during this time incurs a largedelay and it is assumed the delay is acceptable.

A battery 830 may power the platform 800, although in some examples theplatform 800 may be mounted deployed in a fixed location, and may have apower supply coupled to an electrical grid. The battery 830 may be alithium ion battery, a metal-air battery, such as a zinc-air battery, analuminum-air battery, a lithium-air battery, and the like. In someimplementations, such as in V2X applications, the battery 830 may be atypical lead-acid automotive battery.

In some implementations, the battery 830 may be a “smart battery,” whichincludes or is coupled with a Battery Management System (BMS) or batterymonitoring integrated circuitry. The BMS may be included in the platform800 to track the state of charge (SoCh) of the battery 830. The BMS maybe used to monitor other parameters of the battery 830 to providefailure predictions, such as the state of health (SoH) and the state offunction (SoF) of the battery 830. The BMS may communicate theinformation of the battery 830 to the application circuitry 805 or othercomponents of the platform 800. The BMS may also include ananalog-to-digital (ADC) convertor that allows the application circuitry805 to directly monitor the voltage of the battery 830 or the currentflow from the battery 830. The battery parameters may be used todetermine actions that the platform 800 may perform, such astransmission frequency, network operation, sensing frequency, and thelike.

A power block, or other power supply coupled to an electrical grid maybe coupled with the BMS to charge the battery 830. In some examples, thepower block XS30 may be replaced with a wireless power receiver toobtain the power wirelessly, for example, through a loop antenna in thecomputer platform 800. In these examples, a wireless battery chargingcircuit may be included in the BMS. The specific charging circuitschosen may depend on the size of the battery 830, and thus, the currentrequired. The charging may be performed using the Airfuel standardpromulgated by the Airfuel Alliance, the Qi wireless charging standardpromulgated by the Wireless Power Consortium, or the Rezence chargingstandard promulgated by the Alliance for Wireless Power, among others.

User interface circuitry 850 includes various input/output (I/O) devicespresent within, or connected to, the platform 800, and includes one ormore user interfaces designed to enable user interaction with theplatform 800 and/or peripheral component interfaces designed to enableperipheral component interaction with the platform 800. The userinterface circuitry 850 includes input device circuitry and outputdevice circuitry. Input device circuitry includes any physical orvirtual means for accepting an input including, inter alia, one or morephysical or virtual buttons (e.g., a reset button), a physical keyboard,keypad, mouse, touchpad, touchscreen, microphones, scanner, headset,and/or the like. The output device circuitry includes any physical orvirtual means for showing information or otherwise conveyinginformation, such as sensor readings, actuator position(s), or otherlike information. Output device circuitry may include any number and/orcombinations of audio or visual display, including, inter alia, one ormore simple visual outputs/indicators (e.g., binary status indicators(e.g., light emitting diodes (LEDs)) and multi-character visual outputs,or more complex outputs such as display devices or touchscreens (e.g.,Liquid Chrystal Displays (LCD), LED displays, quantum dot displays,projectors, etc.), with the output of characters, graphics, multimediaobjects, and the like being generated or produced from the operation ofthe platform 800. The output device circuitry may also include speakersor other audio emitting devices, printer(s), and/or the like. In someembodiments, the sensor circuitry 821 may be used as the input devicecircuitry (e.g., an image capture device, motion capture device, or thelike) and one or more EMCs may be used as the output device circuitry(e.g., an actuator to provide haptic feedback or the like). In anotherexample, NFC circuitry comprising an NFC controller coupled with anantenna element and a processing device may be included to readelectronic tags and/or connect with another NFC-enabled device.Peripheral component interfaces may include, but are not limited to, anon-volatile memory port, a USB port, an audio jack, a power supplyinterface, etc.

Although not shown, the components of platform 800 may communicate withone another using a suitable bus or interconnect (IX) technology, whichmay include any number of technologies, including ISA, EISA, PCI, PCIx,PCIe, a Time-Trigger Protocol (TTP) system, a FlexRay system, or anynumber of other technologies. The bus/IX may be a proprietary bus/IX,for example, used in a SoC based system. Other bus/IX systems may beincluded, such as an I²C interface, an SPI interface, point-to-pointinterfaces, and a power bus, among others.

FIG. 9 illustrates example components of baseband circuitry 910 andradio front end modules (RFEM) 915 in accordance with variousembodiments. The baseband circuitry 910 corresponds to the basebandcircuitry 710 and 810 of FIGS. 7 and 8 , respectively. The RFEM 915corresponds to the RFEM 715 and 815 of FIGS. 7 and 8 , respectively. Asshown, the RFEMs 915 may include Radio Frequency (RF) circuitry 906,front-end module (FEM) circuitry 908, antenna array 911 coupled togetherat least as shown.

The baseband circuitry 910 includes circuitry and/or control logicconfigured to carry out various radio/network protocol and radio controlfunctions that enable communication with one or more radio networks viathe RF circuitry 906. The radio control functions may include, but arenot limited to, signal modulation/demodulation, encoding/decoding, radiofrequency shifting, etc. In some embodiments, modulation/demodulationcircuitry of the baseband circuitry 910 may include Fast-FourierTransform (FFT), precoding, or constellation mapping/demappingfunctionality. In some embodiments, encoding/decoding circuitry of thebaseband circuitry 910 may include convolution, tail-biting convolution,turbo, Viterbi, or Low Density Parity Check (LDPC) encoder/decoderfunctionality. Embodiments of modulation/demodulation andencoder/decoder functionality are not limited to these examples and mayinclude other suitable functionality in other embodiments. The basebandcircuitry 910 is configured to process baseband signals received from areceive signal path of the RF circuitry 906 and to generate basebandsignals for a transmit signal path of the RF circuitry 906. The basebandcircuitry 910 is configured to interface with application circuitry705/805 (see FIGS. 7 and 8 ) for generation and processing of thebaseband signals and for controlling operations of the RF circuitry 906.The baseband circuitry 910 may handle various radio control functions.

The aforementioned circuitry and/or control logic of the basebandcircuitry 910 may include one or more single or multi-core processors.For example, the one or more processors may include a 3G basebandprocessor 904A, a 4G/LTE baseband processor 904B, a 5G/NR basebandprocessor 904C, or some other baseband processor(s) 904D for otherexisting generations, generations in development or to be developed inthe future (e.g., sixth generation (6G), etc.). In other embodiments,some or all of the functionality of baseband processors 904A-D may beincluded in modules stored in the memory 904G and executed via a CentralProcessing Unit (CPU) 904E. In other embodiments, some or all of thefunctionality of baseband processors 904A-D may be provided as hardwareaccelerators (e.g., FPGAs, ASICs, etc.) loaded with the appropriate bitstreams or logic blocks stored in respective memory cells. In variousembodiments, the memory 904G may store program code of a real-time OS(RTOS), which when executed by the CPU 904E (or other basebandprocessor), is to cause the CPU 904E (or other baseband processor) tomanage resources of the baseband circuitry 910, schedule tasks, etc.Examples of the RTOS may include Operating System Embedded (OSE)™provided by Enea®, Nucleus RTOS™ provided by Mentor Graphics®, VersatileReal-Time Executive (VRTX) provided by Mentor Graphics®, ThreadX™provided by Express Logic®, FreeRTOS, REX OS provided by Qualcomm®, OKL4provided by Open Kernel (OK) Labs®, or any other suitable RTOS, such asthose discussed herein. In addition, the baseband circuitry 910 includesone or more audio digital signal processor(s) (DSP) 904F. The audioDSP(s) 904F include elements for compression/decompression and echocancellation and may include other suitable processing elements in otherembodiments.

In some embodiments, each of the processors 904A-904E include respectivememory interfaces to send/receive data to/from the memory 904G. Thebaseband circuitry 910 may further include one or more interfaces tocommunicatively couple to other circuitries/devices, such as aninterface to send/receive data to/from memory external to the basebandcircuitry 910; an application circuitry interface to send/receive datato/from the application circuitry 705/805 of FIGS. 7 -XT); an RFcircuitry interface to send/receive data to/from RF circuitry 906 ofFIG. 9 ; a wireless hardware connectivity interface to send/receive datato/from one or more wireless hardware elements (e.g., Near FieldCommunication (NFC) components, Bluetooth®/Bluetooth® Low Energycomponents, Wi-Fi® components, and/or the like); and a power managementinterface to send/receive power or control signals to/from the PMIC 825.

In alternate embodiments (which may be combined with the above describedembodiments), baseband circuitry 910 comprises one or more digitalbaseband systems, which are coupled with one another via an interconnectsubsystem and to a CPU subsystem, an audio subsystem, and an interfacesubsystem. The digital baseband subsystems may also be coupled to adigital baseband interface and a mixed-signal baseband subsystem viaanother interconnect subsystem. Each of the interconnect subsystems mayinclude a bus system, point-to-point connections, network-on-chip (NOC)structures, and/or some other suitable bus or interconnect technology,such as those discussed herein. The audio subsystem may include DSPcircuitry, buffer memory, program memory, speech processing acceleratorcircuitry, data converter circuitry such as analog-to-digital anddigital-to-analog converter circuitry, analog circuitry including one ormore of amplifiers and filters, and/or other like components. In anaspect of the present disclosure, baseband circuitry 910 may includeprotocol processing circuitry with one or more instances of controlcircuitry (not shown) to provide control functions for the digitalbaseband circuitry and/or radio frequency circuitry (e.g., the radiofront end modules 915).

Although not shown by FIG. 9 , in some embodiments, the basebandcircuitry 910 includes individual processing device(s) to operate one ormore wireless communication protocols (e.g., a “multi-protocol basebandprocessor” or “protocol processing circuitry”) and individual processingdevice(s) to implement PHY layer functions. In these embodiments, thePHY layer functions include the aforementioned radio control functions.In these embodiments, the protocol processing circuitry operates orimplements various protocol layers/entities of one or more wirelesscommunication protocols. In a first example, the protocol processingcircuitry may operate LTE protocol entities and/or 5G/NR protocolentities when the baseband circuitry 910 and/or RF circuitry 906 arepart of mmWave communication circuitry or some other suitable cellularcommunication circuitry. In the first example, the protocol processingcircuitry would operate MAC, RLC, PDCP, SDAP, RRC, and NAS functions. Ina second example, the protocol processing circuitry may operate one ormore IEEE-based protocols when the baseband circuitry 910 and/or RFcircuitry 906 are part of a Wi-Fi communication system. In the secondexample, the protocol processing circuitry would operate Wi-Fi MAC andlogical link control (LLC) functions. The protocol processing circuitrymay include one or more memory structures (e.g., 904G) to store programcode and data for operating the protocol functions, as well as one ormore processing cores to execute the program code and perform variousoperations using the data. The baseband circuitry 910 may also supportradio communications for more than one wireless protocol.

The various hardware elements of the baseband circuitry 910 discussedherein may be implemented, for example, as a solder-down substrateincluding one or more integrated circuits (ICs), a single packaged ICsoldered to a main circuit board or a multi-chip module containing twoor more ICs. In one example, the components of the baseband circuitry910 may be suitably combined in a single chip or chipset, or disposed ona same circuit board. In another example, some or all of the constituentcomponents of the baseband circuitry 910 and RF circuitry 906 may beimplemented together such as, for example, a system on a chip (SoC) orSystem-in-Package (SiP). In another example, some or all of theconstituent components of the baseband circuitry 910 may be implementedas a separate SoC that is communicatively coupled with and RF circuitry906 (or multiple instances of RF circuitry 906). In yet another example,some or all of the constituent components of the baseband circuitry 910and the application circuitry 705/805 may be implemented together asindividual SoCs mounted to a same circuit board (e.g., a “multi-chippackage”).

In some embodiments, the baseband circuitry 910 may provide forcommunication compatible with one or more radio technologies. Forexample, in some embodiments, the baseband circuitry 910 may supportcommunication with an E-UTRAN or other WMAN, a WLAN, a WPAN. Embodimentsin which the baseband circuitry 910 is configured to support radiocommunications of more than one wireless protocol may be referred to asmulti-mode baseband circuitry.

RF circuitry 906 may enable communication with wireless networks usingmodulated electromagnetic radiation through a non-solid medium. Invarious embodiments, the RF circuitry 906 may include switches, filters,amplifiers, etc. to facilitate the communication with the wirelessnetwork. RF circuitry 906 may include a receive signal path, which mayinclude circuitry to down-convert RF signals received from the FEMcircuitry 908 and provide baseband signals to the baseband circuitry910. RF circuitry 906 may also include a transmit signal path, which mayinclude circuitry to up-convert baseband signals provided by thebaseband circuitry 910 and provide RF output signals to the FEMcircuitry 908 for transmission.

In some embodiments, the receive signal path of the RF circuitry 906 mayinclude mixer circuitry 906 a, amplifier circuitry 906 b and filtercircuitry 906 c. In some embodiments, the transmit signal path of the RFcircuitry 906 may include filter circuitry 906 c and mixer circuitry 906a. RF circuitry 906 may also include synthesizer circuitry 906 d forsynthesizing a frequency for use by the mixer circuitry 906 a of thereceive signal path and the transmit signal path. In some embodiments,the mixer circuitry 906 a of the receive signal path may be configuredto down-convert RF signals received from the FEM circuitry 908 based onthe synthesized frequency provided by synthesizer circuitry 906 d. Theamplifier circuitry 906 b may be configured to amplify thedown-converted signals and the filter circuitry 906 c may be a low-passfilter (LPF) or band-pass filter (BPF) configured to remove unwantedsignals from the down-converted signals to generate output basebandsignals. Output baseband signals may be provided to the basebandcircuitry 910 for further processing. In some embodiments, the outputbaseband signals may be zero-frequency baseband signals, although thisis not a requirement. In some embodiments, mixer circuitry 906 a of thereceive signal path may comprise passive mixers, although the scope ofthe embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 906 a of the transmit signalpath may be configured to up-convert input baseband signals based on thesynthesized frequency provided by the synthesizer circuitry 906 d togenerate RF output signals for the FEM circuitry 908. The basebandsignals may be provided by the baseband circuitry 910 and may befiltered by filter circuitry 906 c.

In some embodiments, the mixer circuitry 906 a of the receive signalpath and the mixer circuitry 906 a of the transmit signal path mayinclude two or more mixers and may be arranged for quadraturedownconversion and upconversion, respectively. In some embodiments, themixer circuitry 906 a of the receive signal path and the mixer circuitry906 a of the transmit signal path may include two or more mixers and maybe arranged for image rejection (e.g., Hartley image rejection). In someembodiments, the mixer circuitry 906 a of the receive signal path andthe mixer circuitry 906 a of the transmit signal path may be arrangedfor direct downconversion and direct upconversion, respectively. In someembodiments, the mixer circuitry 906 a of the receive signal path andthe mixer circuitry 906 a of the transmit signal path may be configuredfor super-heterodyne operation.

In some embodiments, the output baseband signals and the input basebandsignals may be analog baseband signals, although the scope of theembodiments is not limited in this respect. In some alternateembodiments, the output baseband signals and the input baseband signalsmay be digital baseband signals. In these alternate embodiments, the RFcircuitry 906 may include analog-to-digital converter (ADC) anddigital-to-analog converter (DAC) circuitry and the baseband circuitry910 may include a digital baseband interface to communicate with the RFcircuitry 906.

In some dual-mode embodiments, a separate radio IC circuitry may beprovided for processing signals for each spectrum, although the scope ofthe embodiments is not limited in this respect.

In some embodiments, the synthesizer circuitry 906 d may be afractional-N synthesizer or a fractional N/N+1 synthesizer, although thescope of the embodiments is not limited in this respect as other typesof frequency synthesizers may be suitable. For example, synthesizercircuitry 906 d may be a delta-sigma synthesizer, a frequencymultiplier, or a synthesizer comprising a phase-locked loop with afrequency divider.

The synthesizer circuitry 906 d may be configured to synthesize anoutput frequency for use by the mixer circuitry 906 a of the RFcircuitry 906 based on a frequency input and a divider control input. Insome embodiments, the synthesizer circuitry 906 d may be a fractionalN/N+1 synthesizer.

In some embodiments, frequency input may be provided by a voltagecontrolled oscillator (VCO), although that is not a requirement. Dividercontrol input may be provided by either the baseband circuitry 910 orthe application circuitry 705/805 depending on the desired outputfrequency. In some embodiments, a divider control input (e.g., N) may bedetermined from a look-up table based on a channel indicated by theapplication circuitry 705/805.

Synthesizer circuitry 906 d of the RF circuitry 906 may include adivider, a delay-locked loop (DLL), a multiplexer and a phaseaccumulator. In some embodiments, the divider may be a dual modulusdivider (DMD) and the phase accumulator may be a digital phaseaccumulator (DPA). In some embodiments, the DMD may be configured todivide the input signal by either N or N+1 (e.g., based on a carry out)to provide a fractional division ratio. In some example embodiments, theDLL may include a set of cascaded, tunable, delay elements, a phasedetector, a charge pump and a D-type flip-flop. In these embodiments,the delay elements may be configured to break a VCO period up into Ndequal packets of phase, where Nd is the number of delay elements in thedelay line. In this way, the DLL provides negative feedback to helpensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuitry 906 d may be configured togenerate a carrier frequency as the output frequency, while in otherembodiments, the output frequency may be a multiple of the carrierfrequency (e.g., twice the carrier frequency, four times the carrierfrequency) and used in conjunction with quadrature generator and dividercircuitry to generate multiple signals at the carrier frequency withmultiple different phases with respect to each other. In someembodiments, the output frequency may be a LO frequency (fLO). In someembodiments, the RF circuitry 906 may include an IQ/polar converter.

FEM circuitry 908 may include a receive signal path, which may includecircuitry configured to operate on RF signals received from antennaarray 911, amplify the received signals and provide the amplifiedversions of the received signals to the RF circuitry 906 for furtherprocessing. FEM circuitry 908 may also include a transmit signal path,which may include circuitry configured to amplify signals fortransmission provided by the RF circuitry 906 for transmission by one ormore of antenna elements of antenna array 911. In various embodiments,the amplification through the transmit or receive signal paths may bedone solely in the RF circuitry 906, solely in the FEM circuitry 908, orin both the RF circuitry 906 and the FEM circuitry 908.

In some embodiments, the FEM circuitry 908 may include a TX/RX switch toswitch between transmit mode and receive mode operation. The FEMcircuitry 908 may include a receive signal path and a transmit signalpath. The receive signal path of the FEM circuitry 908 may include anLNA to amplify received RF signals and provide the amplified received RFsignals as an output (e.g., to the RF circuitry 906). The transmitsignal path of the FEM circuitry 908 may include a power amplifier (PA)to amplify input RF signals (e.g., provided by RF circuitry 906), andone or more filters to generate RF signals for subsequent transmissionby one or more antenna elements of the antenna array 911.

The antenna array 911 comprises one or more antenna elements, each ofwhich is configured convert electrical signals into radio waves totravel through the air and to convert received radio waves intoelectrical signals. For example, digital baseband signals provided bythe baseband circuitry 910 is converted into analog RF signals (e.g.,modulated waveform) that will be amplified and transmitted via theantenna elements of the antenna array 911 including one or more antennaelements (not shown). The antenna elements may be omnidirectional,direction, or a combination thereof. The antenna elements may be formedin a multitude of arranges as are known and/or discussed herein. Theantenna array 911 may comprise microstrip antennas or printed antennasthat are fabricated on the surface of one or more printed circuitboards. The antenna array 911 may be formed in as a patch of metal foil(e.g., a patch antenna) in a variety of shapes, and may be coupled withthe RF circuitry 906 and/or FEM circuitry 908 using metal transmissionlines or the like.

Processors of the application circuitry 705/805 and processors of thebaseband circuitry 910 may be used to execute elements of one or moreinstances of a protocol stack. For example, processors of the basebandcircuitry 910, alone or in combination, may be used execute Layer 3,Layer 2, or Layer 1 functionality, while processors of the applicationcircuitry 705/805 may utilize data (e.g., packet data) received fromthese layers and further execute Layer 4 functionality (e.g., TCP andUDP layers). As referred to herein, Layer 3 may comprise a RRC layer,described in further detail below. As referred to herein, Layer 2 maycomprise a MAC layer, an RLC layer, and a PDCP layer, described infurther detail below. As referred to herein, Layer 1 may comprise a PHYlayer of a UE/RAN node, described in further detail below.

FIG. 10 illustrates various protocol functions that may be implementedin a wireless communication device according to various embodiments. Inparticular, FIG. 10 includes an arrangement 1000 showinginterconnections between various protocol layers/entities. The followingdescription of FIG. 10 is provided for various protocol layers/entitiesthat operate in conjunction with the 5G/NR system standards and LTEsystem standards, but some or all of the aspects of FIG. 10 may beapplicable to other wireless communication network systems as well.

The protocol layers of arrangement 1000 may include one or more of PHY1010, MAC 1020, RLC 1030, PDCP 1040, SDAP 1047, RRC 1055, and NAS layer1057, in addition to other higher layer functions not illustrated. Theprotocol layers may include one or more service access points (e.g.,items 1059, 1056, 1050, 1049, 1045, 1035, 1025, and 1015 in FIG. 10 )that may provide communication between two or more protocol layers.

The PHY 1010 may transmit and receive physical layer signals 1005 thatmay be received from or transmitted to one or more other communicationdevices. The physical layer signals 1005 may comprise one or morephysical channels, such as those discussed herein. The PHY 1010 mayfurther perform link adaptation or adaptive modulation and coding (AMC),power control, cell search (e.g., for initial synchronization andhandover purposes), and other measurements used by higher layers, suchas the RRC 1055. The PHY 1010 may still further perform error detectionon the transport channels, forward error correction (FEC)coding/decoding of the transport channels, modulation/demodulation ofphysical channels, interleaving, rate matching, mapping onto physicalchannels, and MIMO antenna processing. In embodiments, an instance ofPHY 1010 may process requests from and provide indications to aninstance of MAC 1020 via one or more PHY-SAP 1015. According to someembodiments, requests and indications communicated via PHY-SAP 1015 maycomprise one or more transport channels.

Instance(s) of MAC 1020 may process requests from, and provideindications to, an instance of RLC 1030 via one or more MAC-SAPs 1025.These requests and indications communicated via the MAC-SAP 1025 maycomprise one or more logical channels. The MAC 1020 may perform mappingbetween the logical channels and transport channels, multiplexing of MACSDUs from one or more logical channels onto TBs to be delivered to PHY1010 via the transport channels, de-multiplexing MAC SDUs to one or morelogical channels from TBs delivered from the PHY 1010 via transportchannels, multiplexing MAC SDUs onto TBs, scheduling informationreporting, error correction through HARQ, and logical channelprioritization.

Instance(s) of RLC 1030 may process requests from and provideindications to an instance of PDCP 1040 via one or more radio linkcontrol service access points (RLC-SAP) 1035. These requests andindications communicated via RLC-SAP 1035 may comprise one or more RLCchannels. The RLC 1030 may operate in a plurality of modes of operation,including: Transparent Mode (TM), Unacknowledged Mode (UM), andAcknowledged Mode (AM). The RLC 1030 may execute transfer of upper layerprotocol data units (PDUs), error correction through automatic repeatrequest (ARQ) for AM data transfers, and concatenation, segmentation andreassembly of RLC SDUs for UM and AM data transfers. The RLC 1030 mayalso execute re-segmentation of RLC data PDUs for AM data transfers,reorder RLC data PDUs for UM and AM data transfers, detect duplicatedata for UM and AM data transfers, discard RLC SDUs for UM and AM datatransfers, detect protocol errors for AM data transfers, and perform RLCre-establishment.

Instance(s) of PDCP 1040 may process requests from and provideindications to instance(s) of RRC 1055 and/or instance(s) of SDAP 1047via one or more packet data convergence protocol service access points(PDCP-SAP) 1045. These requests and indications communicated viaPDCP-SAP 1045 may comprise one or more radio bearers. The PDCP 1040 mayexecute header compression and decompression of IP data, maintain PDCPSequence Numbers (SNs), perform in-sequence delivery of upper layer PDUsat re-establishment of lower layers, eliminate duplicates of lower layerSDUs at re-establishment of lower layers for radio bearers mapped on RLCAM, cipher and decipher control plane data, perform integrity protectionand integrity verification of control plane data, control timer-baseddiscard of data, and perform security operations (e.g., ciphering,deciphering, integrity protection, integrity verification, etc.).

Instance(s) of SDAP 1047 may process requests from and provideindications to one or more higher layer protocol entities via one ormore SDAP-SAP 1049. These requests and indications communicated viaSDAP-SAP 1049 may comprise one or more QoS flows. The SDAP 1047 may mapQoS flows to DRBs, and vice versa, and may also mark QFIs in DL and ULpackets. A single SDAP entity 1047 may be configured for an individualPDU session. In the UL direction, the NG-RAN 410 may control the mappingof QoS Flows to DRB(s) in two different ways, reflective mapping orexplicit mapping. For reflective mapping, the SDAP 1047 of a UE 401 maymonitor the QFIs of the DL packets for each DRB, and may apply the samemapping for packets flowing in the UL direction. For a DRB, the SDAP1047 of the UE 401 may map the UL packets belonging to the QoS flows(s)corresponding to the QoS flow ID(s) and PDU session observed in the DLpackets for that DRB. To enable reflective mapping, the NG-RAN 610 maymark DL packets over the Uu interface with a QoS flow ID. The explicitmapping may involve the RRC 1055 configuring the SDAP 1047 with anexplicit QoS flow to DRB mapping rule, which may be stored and followedby the SDAP 1047. In embodiments, the SDAP 1047 may only be used in NRimplementations and may not be used in LTE implementations.

The RRC 1055 may configure, via one or more management service accesspoints (M-SAP), aspects of one or more protocol layers, which mayinclude one or more instances of PHY 1010, MAC 1020, RLC 1030, PDCP 1040and SDAP 1047. In embodiments, an instance of RRC 1055 may processrequests from and provide indications to one or more NAS entities 1057via one or more RRC-SAPs 1056. The main services and functions of theRRC 1055 may include broadcast of system information (e.g., included inMIBs or SIBs related to the NAS), broadcast of system informationrelated to the access stratum (AS), paging, establishment, maintenanceand release of an RRC connection between the UE 401 and RAN 410 (e.g.,RRC connection paging, RRC connection establishment, RRC connectionmodification, and RRC connection release), establishment, configuration,maintenance and release of point to point Radio Bearers, securityfunctions including key management, inter-RAT mobility, and measurementconfiguration for UE measurement reporting. The MIBs and SIBs maycomprise one or more IEs, which may each comprise individual data fieldsor data structures.

The NAS 1057 may form the highest stratum of the control plane betweenthe UE 401 and the AMF 621. The NAS 1057 may support the mobility of theUEs 401 and the session management procedures to establish and maintainIP connectivity between the UE 401 and a P-GW in LTE systems.

According to various embodiments, one or more protocol entities ofarrangement 1000 may be implemented in UEs 401, RAN nodes 411, AMF 621in NR implementations or MME 521 in LTE implementations, UPF 602 in NRimplementations or S-GW 522 and P-GW 523 in LTE implementations, or thelike to be used for control plane or user plane communications protocolstack between the aforementioned devices. In such embodiments, one ormore protocol entities that may be implemented in one or more of UE 401,gNB 411, AMF 621, etc. may communicate with a respective peer protocolentity that may be implemented in or on another device using theservices of respective lower layer protocol entities to perform suchcommunication. In some embodiments, a gNB-CU of the gNB 411 may host theRRC 1055, SDAP 1047, and PDCP 1040 of the gNB that controls theoperation of one or more gNB-DUs, and the gNB-DUs of the gNB 411 mayeach host the RLC 1030, MAC 1020, and PHY 1010 of the gNB 411.

In a first example, a control plane protocol stack may comprise, inorder from highest layer to lowest layer, NAS 1057, RRC 1055, PDCP 1040,RLC 1030, MAC 1020, and PHY 1010. In this example, upper layers 1060 maybe built on top of the NAS 1057, which includes an IP layer 1061, anSCTP 1062, and an application layer signaling protocol (AP) 1063.

In NR implementations, the AP 1063 may be an NG application protocollayer (NGAP or NG-AP) 1063 for the NG interface 413 defined between theNG-RAN node 411 and the AMF 621, or the AP 1063 may be an Xn applicationprotocol layer (XnAP or Xn-AP) 1063 for the Xn interface 412 that isdefined between two or more RAN nodes 411.

The NG-AP 1063 may support the functions of the NG interface 413 and maycomprise Elementary Procedures (EPs). An NG-AP EP may be a unit ofinteraction between the NG-RAN node 411 and the AMF 621. The NG-AP 1063services may comprise two groups: UE-associated services (e.g., servicesrelated to a UE 401, 402) and non-UE-associated services (e.g., servicesrelated to the whole NG interface instance between the NG-RAN node 411and AMF 621). These services may include functions including, but notlimited to: a paging function for the sending of paging requests toNG-RAN nodes 411 involved in a particular paging area; a UE contextmanagement function for allowing the AMF 621 to establish, modify,and/or release a UE context in the AMF 621 and the NG-RAN node 411; amobility function for UEs 401 in ECM-CONNECTED mode for intra-system HOsto support mobility within NG-RAN and inter-system HOs to supportmobility from/to EPS systems; a NAS Signaling Transport function fortransporting or rerouting NAS messages between UE 401 and AMF 621; a NASnode selection function for determining an association between the AMF621 and the UE 401; NG interface management function(s) for setting upthe NG interface and monitoring for errors over the NG interface; awarning message transmission function for providing means to transferwarning messages via NG interface or cancel ongoing broadcast of warningmessages; a Configuration Transfer function for requesting andtransferring of RAN configuration information (e.g., SON information,performance measurement (PM) data, etc.) between two RAN nodes 411 viaCN 420; and/or other like functions.

The XnAP 1063 may support the functions of the Xn interface 412 and maycomprise XnAP basic mobility procedures and XnAP global procedures. TheXnAP basic mobility procedures may comprise procedures used to handle UEmobility within the NG RAN 411 (or E-UTRAN 510), such as handoverpreparation and cancellation procedures, SN Status Transfer procedures,UE context retrieval and UE context release procedures, RAN pagingprocedures, dual connectivity related procedures, and the like. The XnAPglobal procedures may comprise procedures that are not related to aspecific UE 401, such as Xn interface setup and reset procedures, NG-RANupdate procedures, cell activation procedures, and the like.

In LTE implementations, the AP 1063 may be an S1 Application Protocollayer (S1-AP) 1063 for the S1 interface 413 defined between an E-UTRANnode 411 and an MME, or the AP 1063 may be an X2 application protocollayer (X2AP or X2-AP) 1063 for the X2 interface 412 that is definedbetween two or more E-UTRAN nodes 411.

The S1 Application Protocol layer (S1-AP) 1063 may support the functionsof the S1 interface, and similar to the NG-AP discussed previously, theS1-AP may comprise S1-AP EPs. An S1-AP EP may be a unit of interactionbetween the E-UTRAN node 411 and an MME 521 within an LTE CN 420. TheS1-AP 1063 services may comprise two groups: UE-associated services andnon UE-associated services. These services perform functions including,but not limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UEcapability indication, mobility, NAS signaling transport, RANInformation Management (RIM), and configuration transfer.

The X2AP 1063 may support the functions of the X2 interface 412 and maycomprise X2AP basic mobility procedures and X2AP global procedures. TheX2AP basic mobility procedures may comprise procedures used to handle UEmobility within the E-UTRAN 420, such as handover preparation andcancellation procedures, SN Status Transfer procedures, UE contextretrieval and UE context release procedures, RAN paging procedures, dualconnectivity related procedures, and the like. The X2AP globalprocedures may comprise procedures that are not related to a specific UE401, such as X2 interface setup and reset procedures, load indicationprocedures, error indication procedures, cell activation procedures, andthe like.

The SCTP layer (alternatively referred to as the SCTP/IP layer) 1062 mayprovide guaranteed delivery of application layer messages (e.g., NGAP orXnAP messages in NR implementations, or S1-AP or X2AP messages in LTEimplementations). The SCTP 1062 may ensure reliable delivery ofsignaling messages between the RAN node 411 and the AMF 621/MME 521based, in part, on the IP protocol, supported by the IP 1061. TheInternet Protocol layer (IP) 1061 may be used to perform packetaddressing and routing functionality. In some implementations the IPlayer 1061 may use point-to-point transmission to deliver and conveyPDUs. In this regard, the RAN node 411 may comprise L2 and L1 layercommunication links (e.g., wired or wireless) with the MME/AMF toexchange information.

In a second example, a user plane protocol stack may comprise, in orderfrom highest layer to lowest layer, SDAP 1047, PDCP 1040, RLC 1030, MAC1020, and PHY 1010. The user plane protocol stack may be used forcommunication between the UE 401, the RAN node 411, and UPF 602 in NRimplementations or an S-GW 522 and P-GW 523 in LTE implementations. Inthis example, upper layers 1051 may be built on top of the SDAP 1047,and may include a user datagram protocol (UDP) and IP security layer(UDP/IP) 1052, a General Packet Radio Service (GPRS) Tunneling Protocolfor the user plane layer (GTP-U) 1053, and a User Plane PDU layer (UPPDU) 1063.

The transport network layer 1054 (also referred to as a “transportlayer”) may be built on IP transport, and the GTP-U 1053 may be used ontop of the UDP/IP layer 1052 (comprising a UDP layer and IP layer) tocarry user plane PDUs (UP-PDUs). The IP layer (also referred to as the“Internet layer”) may be used to perform packet addressing and routingfunctionality. The IP layer may assign IP addresses to user data packetsin any of IPv4, IPv6, or PPP formats, for example.

The GTP-U 1053 may be used for carrying user data within the GPRS corenetwork and between the radio access network and the core network. Theuser data transported can be packets in any of IPv4, IPv6, or PPPformats, for example. The UDP/IP 1052 may provide checksums for dataintegrity, port numbers for addressing different functions at the sourceand destination, and encryption and authentication on the selected dataflows. The RAN node 411 and the S-GW 522 may utilize an S1-U interfaceto exchange user plane data via a protocol stack comprising an L1 layer(e.g., PHY 1010), an L2 layer (e.g., MAC 1020, RLC 1030, PDCP 1040,and/or SDAP 1047), the UDP/IP layer 1052, and the GTP-U 1053. The S-GW522 and the P-GW 523 may utilize an S5/S8a interface to exchange userplane data via a protocol stack comprising an L1 layer, an L2 layer, theUDP/IP layer 1052, and the GTP-U 1053. As discussed previously, NASprotocols may support the mobility of the UE 401 and the sessionmanagement procedures to establish and maintain IP connectivity betweenthe UE 401 and the P-GW 523.

Moreover, although not shown by FIG. 10 , an application layer may bepresent above the AP 1063 and/or the transport network layer 1054. Theapplication layer may be a layer in which a user of the UE 401, RAN node411, or other network element interacts with software applications beingexecuted, for example, by application circuitry 705 or applicationcircuitry 805, respectively. The application layer may also provide oneor more interfaces for software applications to interact withcommunications systems of the UE 401 or RAN node 411, such as thebaseband circuitry 910. In some implementations the IP layer and/or theapplication layer may provide the same or similar functionality aslayers 5-7, or portions thereof, of the Open Systems Interconnection(OSI) model (e.g., OSI Layer 7—the application layer, OSI Layer 6—thepresentation layer, and OSI Layer 5—the session layer).

FIG. 11 illustrates components of a core network in accordance withvarious embodiments. The components of the CN 520 may be implemented inone physical node or separate physical nodes including components toread and execute instructions from a machine-readable orcomputer-readable medium (e.g., a non-transitory machine-readablestorage medium). In embodiments, the components of CN 620 may beimplemented in a same or similar manner as discussed herein with regardto the components of CN 520. In some embodiments, NFV is utilized tovirtualize any or all of the above-described network node functions viaexecutable instructions stored in one or more computer-readable storagemediums (described in further detail below). A logical instantiation ofthe CN 520 may be referred to as a network slice 1101, and individuallogical instantiations of the CN 520 may provide specific networkcapabilities and network characteristics. A logical instantiation of aportion of the CN 520 may be referred to as a network sub-slice 1102(e.g., the network sub-slice 1102 is shown to include the P-GW 523 andthe PCRF 526).

As used herein, the terms “instantiate,” “instantiation,” and the likemay refer to the creation of an instance, and an “instance” may refer toa concrete occurrence of an object, which may occur, for example, duringexecution of program code. A network instance may refer to informationidentifying a domain, which may be used for traffic detection androuting in case of different IP domains or overlapping IP addresses. Anetwork slice instance may refer to a set of network functions (NFs)instances and the resources (e.g., compute, storage, and networkingresources) required to deploy the network slice.

With respect to 5G systems (see, e.g., FIG. 6 ), a network slice alwayscomprises a RAN part and a CN part. The support of network slicingrelies on the principle that traffic for different slices is handled bydifferent PDU sessions. The network can realize the different networkslices by scheduling and also by providing different L1/L2configurations. The UE 601 provides assistance information for networkslice selection in an appropriate RRC message, if it has been providedby NAS. While the network can support large number of slices, the UEneed not support more than 8 slices simultaneously.

A network slice may include the CN 620 control plane and user plane NFs,NG-RANs 610 in a serving PLMN, and a N3IWF functions in the servingPLMN. Individual network slices may have different S-NSSAI and/or mayhave different SSTs. NSSAI includes one or more S-NSSAIs, and eachnetwork slice is uniquely identified by an S-NSSAI. Network slices maydiffer for supported features and network functions optimizations,and/or multiple network slice instances may deliver the sameservice/features but for different groups of UEs 601 (e.g., enterpriseusers). For example, individual network slices may deliver differentcommitted service(s) and/or may be dedicated to a particular customer orenterprise. In this example, each network slice may have differentS-NSSAIs with the same SST but with different slice differentiators.Additionally, a single UE may be served with one or more network sliceinstances simultaneously via a 5G AN and associated with eight differentS-NSSAIs. Moreover, an AMF 621 instance serving an individual UE 601 maybelong to each of the network slice instances serving that UE.

Network Slicing in the NG-RAN 610 involves RAN slice awareness. RANslice awareness includes differentiated handling of traffic fordifferent network slices, which have been pre-configured. Sliceawareness in the NG-RAN 610 is introduced at the PDU session level byindicating the S-NSSAI corresponding to a PDU session in all signalingthat includes PDU session resource information. How the NG-RAN 610supports the slice enabling in terms of NG-RAN functions (e.g., the setof network functions that comprise each slice) is implementationdependent. The NG-RAN 610 selects the RAN part of the network sliceusing assistance information provided by the UE 601 or the 5GC 620,which unambiguously identifies one or more of the pre-configured networkslices in the PLMN. The NG-RAN 610 also supports resource management andpolicy enforcement between slices as per SLAs. A single NG-RAN node maysupport multiple slices, and the NG-RAN 610 may also apply anappropriate RRM policy for the SLA in place to each supported slice. TheNG-RAN 610 may also support QoS differentiation within a slice.

The NG-RAN 610 may also use the UE assistance information for theselection of an AMF 621 during an initial attach, if available. TheNG-RAN 610 uses the assistance information for routing the initial NASto an AMF 621. If the NG-RAN 610 is unable to select an AMF 621 usingthe assistance information, or the UE 601 does not provide any suchinformation, the NG-RAN 610 sends the NAS signaling to a default AMF621, which may be among a pool of AMFs 621. For subsequent accesses, theUE 601 provides a temp ID, which is assigned to the UE 601 by the 5GC620, to enable the NG-RAN 610 to route the NAS message to theappropriate AMF 621 as long as the temp ID is valid. The NG-RAN 610 isaware of, and can reach, the AMF 621 that is associated with the tempID. Otherwise, the method for initial attach applies.

The NG-RAN 610 supports resource isolation between slices. NG-RAN 610resource isolation may be achieved by means of RRM policies andprotection mechanisms that should avoid that shortage of sharedresources if one slice breaks the service level agreement for anotherslice. In some implementations, it is possible to fully dedicate NG-RAN610 resources to a certain slice. How NG-RAN 610 supports resourceisolation is implementation dependent.

Some slices may be available only in part of the network. Awareness inthe NG-RAN 610 of the slices supported in the cells of its neighbors maybe beneficial for inter-frequency mobility in connected mode. The sliceavailability may not change within the UE's registration area. TheNG-RAN 610 and the 5GC 620 are responsible to handle a service requestfor a slice that may or may not be available in a given area. Admissionor rejection of access to a slice may depend on factors such as supportfor the slice, availability of resources, support of the requestedservice by NG-RAN 610.

The UE 601 may be associated with multiple network slicessimultaneously. In case the UE 601 is associated with multiple slicessimultaneously, only one signaling connection is maintained, and forintra-frequency cell reselection, the UE 601 tries to camp on the bestcell. For inter-frequency cell reselection, dedicated priorities can beused to control the frequency on which the UE 601 camps. The 5GC 620 isto validate that the UE 601 has the rights to access a network slice.Prior to receiving an Initial Context Setup Request message, the NG-RAN610 may be allowed to apply some provisional/local policies, based onawareness of a particular slice that the UE 601 is requesting to access.During the initial context setup, the NG-RAN 610 is informed of theslice for which resources are being requested.

NFV architectures and infrastructures may be used to virtualize one ormore NFs, alternatively performed by proprietary hardware, onto physicalresources comprising a combination of industry-standard server hardware,storage hardware, or switches. In other words, NFV systems can be usedto execute virtual or reconfigurable implementations of one or more EPCcomponents/functions.

FIG. 12 is a block diagram illustrating components, according to someexample embodiments, of a system 1200 to support NFV. The system 1200 isillustrated as including a VIM 1202, an NFVI 1204, an VNFM 1206, VNFs1208, an EM 1210, an NFVO 1212, and a NM 1214.

The VIM 1202 manages the resources of the NFVI 1204. The NFVI 1204 caninclude physical or virtual resources and applications (includinghypervisors) used to execute the system 1200. The VIM 1202 may managethe life cycle of virtual resources with the NFVI 1204 (e.g., creation,maintenance, and tear down of VMs associated with one or more physicalresources), track VM instances, track performance, fault and security ofVM instances and associated physical resources, and expose VM instancesand associated physical resources to other management systems.

The VNFM 1206 may manage the VNFs 1208. The VNFs 1208 may be used toexecute EPC components/functions. The VNFM 1206 may manage the lifecycle of the VNFs 1208 and track performance, fault and security of thevirtual aspects of VNFs 1208. The EM 1210 may track the performance,fault and security of the functional aspects of VNFs 1208. The trackingdata from the VNFM 1206 and the EM 1210 may comprise, for example, PMdata used by the VIM 1202 or the NFVI 1204. Both the VNFM 1206 and theEM 1210 can scale up/down the quantity of VNFs of the system 1200.

The NFVO 1212 may coordinate, authorize, release and engage resources ofthe NFVI 1204 in order to provide the requested service (e.g., toexecute an EPC function, component, or slice). The NM 1214 may provide apackage of end-user functions with the responsibility for the managementof a network, which may include network elements with VNFs,non-virtualized network functions, or both (management of the VNFs mayoccur via the EM 1210).

FIG. 13 is a block diagram illustrating components, according to someexample embodiments, able to read instructions from a machine-readableor computer-readable medium (e.g., a non-transitory machine-readablestorage medium) and perform any one or more of the methodologiesdiscussed herein. Specifically, FIG. 13 shows a diagrammaticrepresentation of hardware resources 1300 including one or moreprocessors (or processor cores) 1310, one or more memory/storage devices1320, and one or more communication resources 1330, each of which may becommunicatively coupled via a bus 1340. For embodiments where nodevirtualization (e.g., NFV) is utilized, a hypervisor 1302 may beexecuted to provide an execution environment for one or more networkslices/sub-slices to utilize the hardware resources 1300.

The processors 1310 may include, for example, a processor 1312 and aprocessor 1314. The processor(s) 1310 may be, for example, a centralprocessing unit (CPU), a reduced instruction set computing (RISC)processor, a complex instruction set computing (CISC) processor, agraphics processing unit (GPU), a DSP such as a baseband processor, anASIC, an FPGA, a radio-frequency integrated circuit (RFIC), anotherprocessor (including those discussed herein), or any suitablecombination thereof.

The memory/storage devices 1320 may include main memory, disk storage,or any suitable combination thereof. The memory/storage devices 1320 mayinclude, but are not limited to, any type of volatile or nonvolatilememory such as dynamic random access memory (DRAM), static random accessmemory (SRAM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), Flashmemory, solid-state storage, etc.

The communication resources 1330 may include interconnection or networkinterface components or other suitable devices to communicate with oneor more peripheral devices 1304 or one or more databases 1306 via anetwork 1308. For example, the communication resources 1330 may includewired communication components (e.g., for coupling via USB), cellularcommunication components, NFC components, Bluetooth® (or Bluetooth® LowEnergy) components, Wi-Fi® components, and other communicationcomponents.

Instructions 1350 may comprise software, a program, an application, anapplet, an app, or other executable code for causing at least any of theprocessors 1310 to perform any one or more of the methodologiesdiscussed herein. The instructions 1350 may reside, completely orpartially, within at least one of the processors 1310 (e.g., within theprocessor's cache memory), the memory/storage devices 1320, or anysuitable combination thereof. Furthermore, any portion of theinstructions 1350 may be transferred to the hardware resources 1300 fromany combination of the peripheral devices 1304 or the databases 1306.Accordingly, the memory of processors 1310, the memory/storage devices1320, the peripheral devices 1304, and the databases 1306 are examplesof computer-readable and machine-readable media.

Example Procedures

In some embodiments, the electronic device(s), network(s), system(s),chip(s) or component(s), or portions or implementations thereof, ofFIGS. 4-13 , or some other Figure herein, may be configured to performone or more processes, techniques, or methods as described herein, orportions thereof. One such process is depicted in FIG. 14 . For example,the process may include receiving or causing to receive a CSI report,wherein the CSI report comprising a channel quality indicator (CQI), arank indicator (RI), and a precoding matrix indicator (PMI) (Step 1410);constructing or causing to construct a precoding matrix based on alinear combination of a plurality of mutually orthogonal digital Fouriertransformation (DFT) spatial beams (Step 1420); determining or causingto determine a number of bits for the PMI of the precoding matrix (Step1430); determining or causing to determine a space frequency matrixbased, at least in part, on the number of bits for the PMI and theprecoding matrix (Step 1440); compressing or causing to compress thespace frequency matrix (Step 1450); and determining or causing todetermine a compressed PMI based, at least in part, on the spacefrequency matrix (Step 1460).

For one or more embodiments, at least one of the components set forth inone or more of the preceding figures may be configured to perform one ormore operations, techniques, processes, and/or methods as set forth inthe example section below. For example, the baseband circuitry asdescribed above in connection with one or more of the preceding figuresmay be configured to operate in accordance with one or more of theexamples set forth below. For another example, circuitry associated witha UE, base station, network element, etc. as described above inconnection with one or more of the preceding figures may be configuredto operate in accordance with one or more of the examples set forthbelow in the example section. For yet another example, an apparatus maybe configured to operate in accordance with one or more examples setforth below. For one more example, an apparatus may comprise means foroperating in accordance with one or more examples set forth below.

EXAMPLES

Examples described herein are illustrative not exhaustive.

Example 1 may include a method of precoding matrix indicator (PMI)reporting at a user equipment (UE) for codebooks based on a linearcombination of spatial beams, comprising:

configuring or causing to configure channel state information (CSI)reporting at the UE;

configuring or causing to configure codebooks of precoding matrixes;

configuring or causing to configure multiple sets of codebookparameters;

determining or causing to determine a PMI according to the configuredcodebook parameters;

calculating or causing to calculate the PMI by the UE in accordance withthe received CSI configuration and codebook configuration; and

reporting or causing to report the PMI by the UE.

Example 2 may include the method of example 1 or some other exampleherein, wherein codebooks are defined for a set of ranks.

Example 3 may include the method of example 2 or some other exampleherein, wherein each column of precoding matrix corresponds to a spatiallayer in the codebooks constructed by a linear combination of spatialbeams.

Example 4 may include the method of example 3 or some other exampleherein, wherein coefficients of the linear combination are defined for aset of frequency resources.

Example 5 may include the method of example 4 or some other exampleherein, wherein a frequency resource is a sub-band configured for CSIreporting.

Example 6 may include the method of example 4 or some other exampleherein, wherein a frequency resource is a sub-band in an activebandwidth part.

Example 7 may include the method of example 4 or some other exampleherein, wherein a frequency resource is a physical resource blockconfigured for CSI reporting.

Example 8 may include the method of example 4 or some other exampleherein, wherein a frequency resource is a physical resource block withinan active bandwidth part.

Example 9 may include the method of example 4 or some other exampleherein, wherein coefficients of a linear combination for a spatial beamand a set of frequency resources form a vector y.

Example 10 may include the method of example 9 or some other exampleherein, wherein vector y is a linear combination of a subset of basisvectors.

Example 11 may include the method of example 10 or some other exampleherein, wherein a basis vector is a column of oversampled discreteFourier transform matrix.

Example 12 may include the method of example 11 or some other exampleherein, wherein an oversampling factor of an oversampled discreteFourier transform matrix is configured by higher layers.

Example 13 may include the method of example 10 or some other exampleherein, wherein a total number of basis vectors is determined from thenumber of frequency resources in the set of frequency resources.

Example 14 may include the method of example 13 or some other exampleherein, wherein a total number of basis vectors is a product of a numberof frequency resources in the set of frequency resources andoversampling factor of the oversampled discrete Fourier transformmatrix.

Example 15 may include the method of example 10 or some other exampleherein, wherein a total number of basis vectors is configured by higherlayers.

Example 16 may include the method of example 10 or some other exampleherein, wherein the number of vectors in the subset of basis vectors isconfigured by higher layers.

Example 17 may include the method of example 15 or some other exampleherein, wherein the number of vectors in the subset of basis vectors isconfigured by higher layers for each rank or for each spatial layer.

Example 18 may include the method of example 10 or some other exampleherein, wherein the number of vectors in the subset of basis vectorsequals to the total number of basis vectors.

Example 19 may include the method of example 10 or some other exampleherein, wherein the number of vectors in the subset of basis vectorsequals to the number of frequency resources in the set of frequencyresources.

Example 20 may include the method of example 10 or some other exampleherein, wherein each basis vector corresponds to a unique value of abasis vector index.

Example 21 may include the method of example 20 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are reported by the UE.

Example 22 may include the method of example 21 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are different for different spatial layers and spatial beams.

Example 23 may include the method of example 21 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are equal to each other for different spatial layers.

Example 24 may include the method of example 21 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are equal to each other for different spatial beams.

Example 25 may include the method of example 21 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are equal to each other for different spatial beams and spatiallayers.

Example 26 may include the method of example 21 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are reported in separate bit fields.

Example 27 may include the method of example 21 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are reported jointly by using an index of a combination.

Example 28 may include the method of example 21 or some other exampleherein, wherein coefficients of a linear combination of the subset ofbasis vectors are quantized and reported by the UE.

Example 29 may include the method of example 28 or some other exampleherein, wherein phases of coefficients of linear combination arequantized and reported by the UE.

Example 30 may include the method of example 29 or some other exampleherein, wherein quantization scheme of phases of coefficients of linearcombination is configured by higher layers.

Example 31 may include the method of example 29 or some other exampleherein, wherein phases of coefficients of linear combination arequantized using a set of values {e^(j2πm/N) ^(PSK) }, m=0, 1, . . . ,N_(PSK)−1.

Example 32 may include the method of example 31 or some other exampleherein, wherein NPSK is configured by higher layers.

Example 33 may include the method of example 29 or some other exampleherein, wherein amplitudes of coefficients of a linear combination arequantized and reported by a UE.

Example 34 may include the method of example 33 or some other exampleherein, wherein a quantization scheme of an amplitude of coefficients oflinear combination is configured by higher layers.

Example 35 may include the method of example 33 or some other exampleherein, wherein phases of coefficients of linear combination arequantized using set of values

$\left\{ \left\lbrack {\frac{1}{2^{n/N_{b}}},0} \right\rbrack \right\},{n = 0},1,\ldots,{N_{a} - 1.}$

Example 36 may include the method of example 35 or some other exampleherein, wherein Na is configured by higher layers.

Example 37 may include the method of example 35 or some other exampleherein, wherein Nb is configured by higher layers.

Example 38 may include the method of example 28 or some other exampleherein, wherein a leading coefficient of a linear combination isquantized and reported by the UE for each spatial beam and spatiallayer.

Example 39 may include the method of example 38 or some other exampleherein, wherein an index of the leading coefficient is reported by theUE.

Example 40 may include the method of example 38 or some other exampleherein, wherein ratios of amplitudes of a coefficient of linearcombination and amplitudes of a leading coefficient of linearcombination are quantized and reported by the UE.

Example 41 may include the method of example 38 or some other exampleherein, wherein a phase of a product of a coefficient of linearcombination and a complex conjugate of a leading coefficient of linearcombination is quantized and reported by the UE.

Example 42 may include the method of example 1 or some other exampleherein, wherein CSI report is comprised of CSI part 1 and CSI part 2.

Example 43 may include the method of example 21 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are reported in CSI part 1.

Example 44 may include the method of example 21 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are reported in CSI part 2.

Example 45 may include the method of example 21 or some other exampleherein, wherein indexes of basis vectors included in the subset of basisvectors are reported in CSI part 1 for a first spatial layer and in CSIpart 2 for a second spatial layer.

Example 46 may include the method of example 29 or some other exampleherein, wherein phases of coefficients of linear combination arereported in CSI part 2.

Example 47 may include the method of example 33 or some other exampleherein, wherein amplitudes of coefficients of linear combination arereported in CSI part 1.

Example 48 may include the method of example 33 or some other exampleherein, wherein amplitudes of coefficients of linear combination arereported in CSI part 2.

Example 49 may include the method of example 33 or some other exampleherein, wherein amplitudes of coefficients of linear combination arereported in CSI part 1 for a first spatial layer and in CSI part 2 for asecond spatial layer.

Example 50 may include the method of example 38 or some other exampleherein, wherein amplitudes of leading coefficients of linear combinationare reported in CSI part 1.

Example 51 may include the method of example 38 or some other exampleherein, wherein amplitudes of leading coefficients of linear combinationare reported in CSI part 2.

Example 52 may include the method of example 38 or some other exampleherein, wherein amplitudes of leading coefficients of linear combinationare reported in CSI part 1 for a first spatial layer and in CSI part 2for a second spatial layer.

Example 53 may include the method of example 47 or some other exampleherein, wherein the number of coefficients of linear combination with 0amplitude is reported in CSI part 1.

Example 54 may include the method of example 47 or some other exampleherein, wherein the number of coefficients of linear combination withnon-zero amplitude is reported in CSI part 1.

Example 55 may include the method of example 51 or some other exampleherein, wherein the number of leading coefficients of linear combinationwith 0 amplitude is reported in CSI part 1.

Example 56 may include the method of example 51 or some other exampleherein, wherein the number of leading coefficients of linear combinationwith non-zero amplitude is reported in CSI part 1.

Example 57 may include the method of example 9 or some other exampleherein, wherein elements of vector y are quantized and reported by theUE for a subset of spatial beams.

Example 58 may include the method of example 57 or some other exampleherein, wherein vector y is a linear combination of a subset of basisvectors for other spatial beams.

Example 59 may include the method of example 58 or some other exampleherein, wherein coefficients of linear combination of a subset of basisvectors and subset of basis vectors are reported by the UE.

Example 60 may include the method of example 57 or some other exampleherein, wherein the subset of spatial beams is determined based onaverage amplitude of vector y.

Example 61 may include the method of example 9 or some other exampleherein, wherein vector y corresponds to the strongest spatial beam.

Example 62 may include method of example 9 or some other example herein,wherein elements of y are real numbers.

Example 63 may include the method of example 62 or some other exampleherein, wherein a vector c is discrete Fourier transform of the vectory.

Example 64 may include the method of example 63 or some other exampleherein, wherein elements of the vector c are divided in two sets C1 andC2.

Example 65 may include the method of example 64 or some other exampleherein, wherein each element from C2 is complex conjugate of an elementfrom C1.

Example 66 may include the method of example 65 or some other exampleherein, wherein a subset of elements from C1 is reported by the UE.

Example 67 may include the method of example 66 or some other exampleherein, wherein a subset of elements from C2 is derived based on thereported coefficients.

Example 68 may include an apparatus for use in precoding matrixindicator (PMI) reporting at a user equipment (UE) for codebooks basedon a linear combination of spatial beams, wherein the apparatuscomprises:

means for configuring channel state information (CSI) reporting at theUE;

means for configuring codebooks of precoding matrixes;

means for configuring multiple sets of codebook parameters;

means for determining a PMI according to the configured codebookparameters;

means for calculating the PMI by the UE in accordance with the receivedCSI configuration and codebook configuration; and

means for reporting the PMI by the UE.

Example 69 may include an apparatus comprising means for performing themethod of any one of examples 2 to 67.

Example 70 may include an apparatus for use in precoding matrixindicator (PMI) reporting at a user equipment (UE) for codebooks basedon a linear combination of spatial beams, wherein the apparatus isconfigured to:

configure channel state information (CSI) reporting at the UE;

configure codebooks of precoding matrixes;

configure multiple sets of codebook parameters;

determine a PMI according to the configured codebook parameters;

calculate the PMI by the UE in accordance with the received CSIconfiguration and codebook configuration; and

report the PMI by the UE.

Example 71 may include a method of frequency domain channel stateinformation (CSI) compression, comprising:

receiving or causing to receive a CSI report, wherein the CSI reportcomprising a channel quality indicator (CQI), a rank indicator (RI), anda precoding matrix indicator (PMI);

constructing or causing to construct a precoding matrix based on alinear combination of a plurality of mutually orthogonal digital Fouriertransformation (DFT) spatial beams;

determining or causing to determine a number of bits for the PMI of theprecoding matrix;

determining or causing to determine a space frequency matrix based, atleast in part, on the number of bits for the PMI and the precodingmatrix;

compressing or causing to compress the space frequency matrix; and

determining or causing to determine a compressed PMI based, at least inpart, on the space frequency matrix.

Example 72 may include the method of example 71 or some other exampleherein, wherein compressing or causing to compress the space frequencymatrix comprises:

compressing or causing to compress the space frequency matrix usinglinear transformation.

Example 73 may include the method of example 71 or some other exampleherein, wherein compressing or causing to compress the space frequencymatrix comprises:

compressing or causing to compress the space frequency matrix usingfrequency domain compression, wherein the frequency domain compressioncomprises multiplying the space frequency matrix with a complex number,the complex number having an arbitrary phase and unit amplitude.

Example 74 may include the method of example 71 or some other exampleherein, wherein compressing or causing to compress the space frequencymatrix comprises:

compressing or causing to compress the space frequency matrix using timedomain compression, wherein the time domain compression comprisesderiving a first set of time domain coefficients from a second set oftime domain coefficients.

Example 75 may include the method of example 71 or some other exampleherein, further comprising:

transmitting or causing to transmit the compressed PMI.

Example 76 may include an apparatus for use in frequency domain channelstate information (CSI) compression, comprising:

means for receiving a CSI report, wherein the CSI report comprising achannel quality indicator (CQI), a rank indicator (RI), and a precodingmatrix indicator (PMI);

means for constructing a precoding matrix based on a linear combinationof a plurality of mutually orthogonal digital Fourier transformation(DFT) spatial beams;

means for determining a number of bits for the PMI of the precodingmatrix;

means for determining a space frequency matrix based, at least in part,on the number of bits for the PMI and the precoding matrix;

means for compressing the space frequency matrix; and

means for determining a compressed PMI based, at least in part, on thespace frequency matrix.

Example 77 may include the apparatus of example 76 or some other exampleherein, wherein the means for compressing the space frequency matrixcomprises:

means 78 compressing the space frequency matrix using lineartransformation.

Example 79 may include the apparatus of example 76 or some other exampleherein, wherein the means for compressing the space frequency matrixcomprises:

means for compressing the space frequency matrix using frequency domaincompression, wherein the frequency domain compression comprisesmultiplying the space frequency matrix with a complex number, thecomplex number having an arbitrary phase and unit amplitude.

Example 80 may include the apparatus of example 76 or some other exampleherein, wherein the means for compressing the space frequency matrixcomprises:

means for compressing the space frequency matrix using time domaincompression, wherein the time domain compression comprises deriving afirst set of time domain coefficients from a second set of time domaincoefficients.

Example 87 may include the apparatus of example 76 or some other exampleherein, further comprising:

means for transmitting the compressed PMI.

Example 82 may include an apparatus for use in frequency domain channelstate information (CSI) compression, configured to:

receive a CSI report, wherein the CSI report comprising a channelquality indicator (CQI), a rank indicator (RI), and a precoding matrixindicator (PMI);

construct a precoding matrix based on a linear combination of aplurality of mutually orthogonal digital Fourier transformation (DFT)spatial beams;

determine a number of bits for the PMI of the precoding matrix;

determine a space frequency matrix based, at least in part, on thenumber of bits for the PMI and the precoding matrix;

compress the space frequency matrix; and

determine a compressed PMI based, at least in part, on the spacefrequency matrix.

Example 83 may include the apparatus of example 82 or some other exampleherein, wherein the apparatus configured to compress the space frequencymatrix comprises the apparatus configured to:

compress the space frequency matrix using linear transformation.

Example 84 may include the apparatus of example 82 or some other exampleherein, wherein the apparatus configured to compress the space frequencymatrix comprises the apparatus configured to:

compress the space frequency matrix using frequency domain compression,wherein the frequency domain compression comprises multiplying the spacefrequency matrix with a complex number, the complex number having anarbitrary phase and unit amplitude.

Example 85 may include the apparatus of example 82 or some other exampleherein, wherein the apparatus configured to compress the space frequencymatrix comprises the apparatus configured to:

compress the space frequency matrix using time domain compression,wherein the time domain compression comprises deriving a first set oftime domain coefficients from a second set of time domain coefficients.

Example 86 may include the apparatus of example 82 or some other exampleherein, wherein the apparatus is further configured to:

transmit the compressed PMI.

Example 87 may include an apparatus configured to perform the method ofany one of examples 1-86.

Example 88 may include an apparatus comprising means to perform one ormore elements of a method described in or related to any of examples1-86, or any other method or process described herein.

Example 89 may include one or more non-transitory computer-readablemedia comprising instructions to cause an electronic device, uponexecution of the instructions by one or more processors of theelectronic device, to perform one or more elements of a method describedin or related to any of examples 1-86, or any other method or processdescribed herein.

Example 90 may include an apparatus comprising logic, modules, orcircuitry to perform one or more elements of a method described in orrelated to any of examples 1-86, or any other method or processdescribed herein.

Example 91 may include a method, technique, or process as described inor related to any of examples 1-86, or portions or parts thereof.

Example 92 may include an apparatus comprising: one or more processorsand one or more computer-readable media comprising instructions that,when executed by the one or more processors, cause the one or moreprocessors to perform the method, techniques, or process as described inor related to any of examples 1-86, or portions thereof.

Example 93 may include a signal as described in or related to any ofexamples 1-86, or portions or parts thereof.

Example 94 may include a signal in a wireless network as shown anddescribed herein.

Example 95 may include a method of communicating in a wireless networkas shown and described herein.

Example 96 may include a system for providing wireless communication asshown and described herein.

Example 97 may include a device for providing wireless communication asshown and described herein.

Example 82 may include a user equipment comprising circuitry configuredto perform at least some portions of the method set forth in any one ofexamples 1-86.

Example 82 may include a base station comprising circuitry configured toperform at least some portion of the method set forth in any one ofexamples 1-86.

Any of the above-described examples may be combined with any otherexample (or combination of examples), unless explicitly statedotherwise. The foregoing description of one or more implementationsprovides illustration and description, but is not intended to beexhaustive or to limit the scope of embodiments to the precise formdisclosed. Modifications and variations are possible in light of theabove teachings or may be acquired from practice of various embodiments.

Abbreviations

For the purposes of the present document, the following abbreviationsmay apply to the examples and embodiments discussed herein.

-   -   3GPP Third Generation Partnership Project    -   4G Fourth Generation    -   5G Fifth Generation    -   5GC 5G Core network    -   ACK Acknowledgement    -   AF Application Function    -   AM Acknowledged Mode    -   AMBR Aggregate Maximum Bit Rate    -   AMF Access and Mobility Management Function    -   AN Access Network    -   ANR Automatic Neighbour Relation    -   AP Application Protocol, Antenna Port, Access Point    -   API Application Programming Interface    -   APN Access Point Name    -   ARP Allocation and Retention Priority    -   ARQ Automatic Repeat Request    -   AS Access Stratum    -   ASN.1 Abstract Syntax Notation One    -   AUSF Authentication Server Function    -   AWGN Additive White Gaussian Noise    -   BCH Broadcast Channel    -   BER Bit Error Ratio    -   BFD Beam Failure Detection    -   BLER Block Error Rate    -   BPSK Binary Phase Shift Keying    -   BRAS Broadband Remote Access Server    -   BSS Business Support System    -   BS Base Station    -   BSR Buffer Status Report    -   BW Bandwidth    -   BWP Bandwidth Part    -   C-RNTI Cell Radio Network Temporary Identity    -   CA Carrier Aggregation, Certification Authority    -   CAPEX CAPital EXpenditure    -   CBRA Contention Based Random Access    -   CC Component Carrier, Country Code, Cryptographic Checksum    -   CCA Clear Channel Assessment    -   CCE Control Channel Element    -   CCCH Common Control Channel    -   CE Coverage Enhancement    -   CDM Content Delivery Network    -   CDMA Code-Division Multiple Access    -   CFRA Contention Free Random Access    -   CG Cell Group    -   CI Cell Identity    -   CID Cell-ID (e.g., positioning method)    -   CIM Common Information Model    -   CIR Carrier to Interference Ratio    -   CK Cipher Key    -   CM Connection Management, Conditional Mandatory    -   CMAS Commercial Mobile Alert Service    -   CMD Command    -   CMS Cloud Management System    -   CO Conditional Optional    -   CoMP Coordinated Multi-Point    -   CORESET Control Resource Set    -   COTS Commercial Off-The-Shelf    -   CP Control Plane, Cyclic Prefix, Connection Point    -   CPD Connection Point Descriptor    -   CPE Customer Premise Equipment    -   CPICH Common Pilot Channel    -   CQI Channel Quality Indicator    -   CPU CSI processing unit, Central Processing Unit    -   C/R Command/Response field bit    -   CRAN Cloud Radio Access Network, Cloud RAN    -   CRB Common Resource Block    -   CRC Cyclic Redundancy Check    -   CRI Channel-State Information Resource Indicator, CSI-RS        Resource Indicator    -   C-RNTI Cell RNTI    -   CS Circuit Switched    -   CSAR Cloud Service Archive    -   CSI Channel-State Information    -   CSI-IM CSI Interference Measurement    -   CSI-RS CSI Reference Signal    -   CSI-RSRP CSI reference signal received power    -   CSI-RSRQ CSI reference signal received quality    -   CSI-SINR CSI signal-to-noise and interference ratio    -   CSMA Carrier Sense Multiple Access    -   CSMA/CA CSMA with collision avoidance    -   CSS Common Search Space, Cell-specific Search Space    -   CTS Clear-to-Send    -   CW Codeword    -   CWS Contention Window Size    -   D2D Device-to-Device    -   DC Dual Connectivity, Direct Current    -   DCI Downlink Control Information    -   DF Deployment Flavour    -   DL Downlink    -   DMTF Distributed Management Task Force    -   DPDK Data Plane Development Kit    -   DM-RS, DMRS Demodulation Reference Signal    -   DN Data network    -   DRB Data Radio Bearer    -   DRS Discovery Reference Signal    -   DRX Discontinuous Reception    -   DSL Domain Specific Language. Digital Subscriber Line    -   DSLAM DSL Access Multiplexer    -   DwPTS Downlink Pilot Time Slot    -   E-LAN Ethernet Local Area Network    -   E2E End-to-End    -   ECCA extended clear channel assessment, extended CCA    -   ECCE Enhanced Control Channel Element, Enhanced CCE    -   ED Energy Detection    -   EDGE Enhanced Datarates for GSM Evolution (GSM Evolution)    -   EGMF Exposure Governance Management Function    -   EGPRS Enhanced GPRS    -   EIR Equipment Identity Register    -   eLAA enhanced Licensed Assisted Access, enhanced LAA    -   EM Element Manager    -   eMBB Enhanced Mobile Broadband    -   EMS Element Management System    -   eNB evolved NodeB, E-UTRAN Node B    -   EN-DC E-UTRA-NR Dual Connectivity    -   EPC Evolved Packet Core    -   EPDCCH enhanced PDCCH, enhanced Physical Downlink Control Cannel    -   EPRE Energy per resource element    -   EPS Evolved Packet System    -   EREG enhanced REG, enhanced resource element groups    -   ETSI European Telecommunications Standards Institute    -   ETWS Earthquake and Tsunami Warning System    -   eUICC embedded UICC, embedded Universal Integrated Circuit Card    -   E-UTRA Evolved UTRA    -   E-UTRAN Evolved UTRAN    -   EV2X Enhanced V2X    -   F1AP F1 Application Protocol    -   F1-C F1 Control plane interface    -   F1-U F1 User plane interface    -   FACCH Fast Associated Control CHannel    -   FACCH/F Fast Associated Control Channel/Full rate    -   FACCH/H Fast Associated Control Channel/Half rate    -   FACH Forward Access Channel    -   FAUSCH Fast Uplink Signalling Channel    -   FB Functional Block    -   FBI Feedback Information    -   FCC Federal Communications Commission    -   FCCH Frequency Correction CHannel    -   FDD Frequency Division Duplex    -   FDM Frequency Division Multiplex    -   FDMA Frequency Division Multiple Access    -   FE Front End    -   FEC Forward Error Correction    -   FFS For Further Study    -   FFT Fast Fourier Transformation    -   feLAA further enhanced Licensed Assisted Access, further        enhanced LAA    -   FN Frame Number    -   FPGA Field-Programmable Gate Array    -   FR Frequency Range    -   G-RNTI GERAN Radio Network Temporary Identity    -   GERAN GSM EDGE RAN, GSM EDGE Radio Access Network    -   GGSN Gateway GPRS Support Node    -   GLONASS GLObal′naya NAvigatsionnaya Sputnikovaya Sistema (Engl.:        Global Navigation Satellite System)    -   gNB Next Generation NodeB    -   gNB-CU gNB-centralized unit, Next Generation NodeB centralized        unit    -   gNB-DU gNB-distributed unit, Next Generation NodeB distributed        unit    -   GNSS Global Navigation Satellite System    -   GPRS General Packet Radio Service    -   GSM Global System for Mobile Communications, Groupe Special        Mobile    -   GTP GPRS Tunneling Protocol    -   GTP-U GPRS Tunnelling Protocol for User Plane    -   GTS Go To Sleep Signal (related to WUS)    -   GUMMEI Globally Unique MME Identifier    -   GUTI Globally Unique Temporary UE Identity    -   HARQ Hybrid ARQ, Hybrid Automatic Repeat Request    -   HANDO, HO Handover    -   HFN HyperFrame Number    -   HHO Hard Handover    -   HLR Home Location Register    -   HN Home Network    -   HO Handover    -   HPLMN Home Public Land Mobile Network    -   HSDPA High Speed Downlink Packet Access    -   HSN Hopping Sequence Number    -   HSPA High Speed Packet Access    -   HSS Home Subscriber Server    -   HSUPA High Speed Uplink Packet Access    -   HTTP Hyper Text Transfer Protocol    -   HTTPS Hyper Text Transfer Protocol Secure (https is http/1.1        over SSL, i.e. port 443)    -   I-Block Information Block    -   ICCID Integrated Circuit Card Identification    -   ICIC Inter-Cell Interference Coordination    -   ID Identity, identifier    -   IDFT Inverse Discrete Fourier Transform    -   IE Information element    -   IBE In-Band Emission    -   IEEE Institute of Electrical and Electronics Engineers    -   IEI Information Element Identifier    -   IEIDL Information Element Identifier Data Length    -   IETF Internet Engineering Task Force    -   IF Infrastructure    -   IM Interference Measurement, Intermodulation, IP Multimedia    -   IMC IMS Credentials    -   IMEI International Mobile Equipment Identity    -   IMGI International mobile group identity    -   IMIP Multimedia Private Identity    -   IMPU IP Multimedia PUblic identity    -   IMS IP Multimedia Subsystem    -   IMSI International Mobile Subscriber Identity    -   IoT Internet of Things    -   IP Internet Protocol    -   Ipsec IP Security, Internet Protocol Security    -   IP-CAN IP-Connectivity Access Network    -   IP-M IP Multicast    -   IPv4 Internet Protocol Version 4    -   IPv6 Internet Protocol Version 6    -   IR Infrared    -   IS In Sync    -   IRP Integration Reference Point    -   ISDN Integrated Services Digital Network    -   ISIM IM Services Identity Module    -   ISO International Organisation for Standardisation    -   ISP Internet Service Provider    -   IWF Interworking-Function    -   I-WLAN Interworking WLAN    -   K Constraint length of the convolutional code, USIM Individual        key    -   kB Kilobyte (1000 bytes)    -   kbps kilo-bits per second    -   Kc Ciphering key    -   Ki Individual subscriber authentication key    -   KPI Key Performance Indicator    -   KQI Key Quality Indicator    -   KSI Key Set Identifier    -   ksps kilo-symbols per second    -   KVM Kernel Virtual Machine    -   L1 Layer 1 (physical layer)    -   L1-RSRP Layer 1 reference signal received power    -   L2Layer 2 (data link layer)    -   L3 Layer 3 (network layer)    -   LAA Licensed Assisted Access    -   LAN Local Area Network    -   LBT Listen Before Talk    -   LCM LifeCycle Management    -   LCR Low Chip Rate    -   LCS Location Services    -   LCID Logical Channel ID    -   LI Layer Indicator    -   LLC Logical Link Control, Low Layer Compatibility    -   LPLMN Local PLMN    -   LPP LTE Positioning Protocol    -   LSB Least Significant Bit    -   LTE Long Term Evolution    -   LWA LTE-WLAN aggregation    -   LWIP LTE/WLAN Radio Level Integration with IPsec Tunnel    -   LTE Long Term Evolution    -   M2M Machine-to-Machine    -   MAC Medium Access Control (protocol layering context)    -   MAC Message authentication code (security/encryption context)    -   MAC-A MAC used for authentication and key agreement (TSG T WG3        context)    -   MAC-I MAC used for data integrity of signalling messages (TSG T        WG3 context)    -   MANO Management and Orchestration    -   MBMS Multimedia Broadcast and Multicast Service    -   MB SFN Multimedia Broadcast multicast service Single Frequency        Network    -   MCC Mobile Country Code    -   MCG Master Cell Group    -   MCOT Maximum Channel Occupancy Time    -   MCS Modulation and coding scheme    -   MDAF Management Data Analytics Function    -   MDAS Management Data Analytics Service    -   MDT Minimization of Drive Tests    -   ME Mobile Equipment    -   MeNB master eNB    -   MER Message Error Ratio    -   MGL Measurement Gap Length    -   MGRP Measurement Gap Repetition Period    -   MIB Master Information Block, Management Information Base    -   MIMO Multiple Input Multiple Output    -   MLC Mobile Location Centre    -   MM Mobility Management    -   MME Mobility Management Entity    -   MN Master Node    -   MO Measurement Object, Mobile Originated    -   MPBCH MTC Physical Broadcast CHannel    -   MPDCCH MTC Physical Downlink Control CHannel    -   MPDSCH MTC Physical Downlink Shared CHannel    -   MPRACH MTC Physical Random Access CHannel    -   MPUSCH MTC Physical Uplink Shared Channel    -   MPLS MultiProtocol Label Switching    -   MS Mobile Station    -   MSB Most Significant Bit    -   MSC Mobile Switching Centre    -   MSI Minimum System Information, MCH Scheduling Information    -   MSID Mobile Station Identifier    -   MSIN Mobile Station Identification Number    -   MSISDN Mobile Subscriber ISDN Number    -   MT Mobile Terminated, Mobile Termination    -   MTC Machine-Type Communications    -   mMTC massive MTC, massive Machine-Type Communications    -   MU-MIMO Multi User MIMO    -   MWUS MTC wake-up signal, MTC WUS    -   NACK Negative Acknowledgement    -   NAI Network Access Identifier    -   NAS Non-Access Stratum, Non-Access Stratum layer    -   NCT Network Connectivity Topology    -   NEC Network Capability Exposure    -   NE-DC NR-E-UTRA Dual Connectivity    -   NEF Network Exposure Function    -   NF Network Function    -   NFP Network Forwarding Path    -   NFPD Network Forwarding Path Descriptor    -   NFV Network Functions Virtualization    -   NFVI NFV Infrastructure    -   NFVO NFV Orchestrator    -   NG Next Generation, Next Gen    -   NGEN-DC NG-RAN E-UTRA-NR Dual Connectivity    -   NM Network Manager    -   NMS Network Management System    -   N-PoP Network Point of Presence    -   NMIB, N-MIB Narrowband MIB    -   NPBCH Narrowband Physical Broadcast CHannel    -   NPDCCH Narrowband Physical Downlink Control CHannel    -   NPDSCH Narrowband Physical Downlink Shared CHannel    -   NPRACH Narrowband Physical Random Access CHannel    -   NPUSCH Narrowband Physical Uplink Shared CHannel    -   NPSS Narrowband Primary Synchronization Signal    -   NSSS Narrowband Secondary Synchronization Signal    -   NR New Radio, Neighbour Relation    -   NRF NF Repository Function    -   NRS Narrowband Reference Signal    -   NS Network Service    -   NSA Non-Standalone operation mode    -   NSD Network Service Descriptor    -   NSR Network Service Record    -   NSSAI Network Slice Selection Assistance Information    -   S-NNSAI Single-NS SAI    -   NSSF Network Slice Selection Function    -   NW Network    -   NWUS Narrowband wake-up signal, Narrowband WUS    -   NZP Non-Zero Power    -   O&M Operation and Maintenance    -   ODU2 Optical channel Data Unit—type 2    -   OFDM Orthogonal Frequency Division Multiplexing    -   OFDMA Orthogonal Frequency Division Multiple Access    -   OOB Out-of-band    -   OOS Out of Sync    -   OPEX OPerating EXpense    -   OSI Other System Information    -   OSS Operations Support System    -   OTA over-the-air    -   PAPR Peak-to-Average Power Ratio    -   PAR Peak to Average Ratio    -   PBCH Physical Broadcast Channel    -   PC Power Control, Personal Computer    -   PCC Primary Component Carrier, Primary CC    -   PCell Primary Cell    -   PCI Physical Cell ID, Physical Cell Identity    -   PCEF Policy and Charging Enforcement Function    -   PCF Policy Control Function    -   PCRF Policy Control and Charging Rules Function    -   PDCP Packet Data Convergence Protocol, Packet Data Convergence        Protocol layer    -   PDCCH Physical Downlink Control Channel    -   PDCP Packet Data Convergence Protocol    -   PDN Packet Data Network, Public Data Network    -   PDSCH Physical Downlink Shared Channel    -   PDU Protocol Data Unit    -   PEI Permanent Equipment Identifiers    -   PFD Packet Flow Description    -   P-GW PDN Gateway    -   PHICH Physical hybrid-ARQ indicator channel    -   PHY Physical layer    -   PLMN Public Land Mobile Network    -   PIN Personal Identification Number    -   PM Performance Measurement    -   PMI Precoding Matrix Indicator    -   PNF Physical Network Function    -   PNFD Physical Network Function Descriptor    -   PNFR Physical Network Function Record    -   POC PTT over Cellular    -   PP, PTP Point-to-Point    -   PPP Point-to-Point Protocol    -   PRACH Physical RACH    -   PRB Physical resource block    -   PRG Physical resource block group    -   ProSe Proximity Services, Proximity-Based Service    -   PRS Positioning Reference Signal    -   PRR Packet Reception Radio    -   PS Packet Services    -   PSBCH Physical Sidelink Broadcast Channel    -   PSDCH Physical Sidelink Downlink Channel    -   PSCCH Physical Sidelink Control Channel    -   PSSCH Physical Sidelink Shared Channel    -   PSCell Primary SCell    -   PSS Primary Synchronization Signal    -   PSTN Public Switched Telephone Network    -   PT-RS Phase-tracking reference signal    -   PTT Push-to-Talk    -   PUCCH Physical Uplink Control Channel    -   PUSCH Physical Uplink Shared Channel    -   QAM Quadrature Amplitude Modulation    -   QCI QoS class of identifier    -   QCL Quasi co-location    -   QFI QoS Flow ID, QoS Flow Identifier    -   QoS Quality of Service    -   QPSK Quadrature (Quaternary) Phase Shift Keying    -   QZSS Quasi-Zenith Satellite System    -   RA-RNTI Random Access RNTI    -   RAB Radio Access Bearer, Random Access Burst    -   RACH Random Access Channel    -   RADIUS Remote Authentication Dial In User Service    -   RAN Radio Access Network    -   RAND RANDom number (used for authentication)    -   RAR Random Access Response    -   RAT Radio Access Technology    -   RAU Routing Area Update    -   RB Resource block, Radio Bearer    -   RBG Resource block group    -   REG Resource Element Group    -   Rel Release    -   REQ REQuest    -   RF Radio Frequency    -   RI Rank Indicator    -   MV Resource indicator value    -   RL Radio Link    -   RLC Radio Link Control, Radio Link Control layer    -   RLC AM RLC Acknowledged Mode    -   RLC UM RLC Unacknowledged Mode    -   RLF Radio Link Failure    -   RLM Radio Link Monitoring    -   RLM-RS Reference Signal for RLM    -   RM Registration Management    -   RMC Reference Measurement Channel    -   RMSI Remaining MSI, Remaining Minimum System Information    -   RN Relay Node    -   RNC Radio Network Controller    -   RNL Radio Network Layer    -   RNTI Radio Network Temporary Identifier    -   ROHC RObust Header Compression    -   RRC Radio Resource Control, Radio Resource Control layer    -   RRM Radio Resource Management    -   RS Reference Signal    -   RSRP Reference Signal Received Power    -   RSRQ Reference Signal Received Quality    -   RSSI Received Signal Strength Indicator    -   RSU Road Side Unit    -   RSTD Reference Signal Time difference    -   RTP Real Time Protocol    -   RTS Ready-To-Send    -   RTT Round Trip Time    -   Rx Reception, Receiving, Receiver    -   S1AP S1 Application Protocol    -   S1-MME S1 for the control plane    -   S1-U S1 for the user plane    -   S-GW Serving Gateway    -   S-RNTI SRNC Radio Network Temporary Identity    -   S-TMSI SAE Temporary Mobile Station Identifier    -   SA Standalone operation mode    -   SAE System Architecture Evolution    -   SAP Service Access Point    -   SAPD Service Access Point Descriptor    -   SAPI Service Access Point Identifier    -   SCC Secondary Component Carrier, Secondary CC    -   SCell Secondary Cell    -   SC-FDMA Single Carrier Frequency Division Multiple Access    -   SCG Secondary Cell Group    -   SCM Security Context Management    -   SCS Subcarrier Spacing    -   SCTP Stream Control Transmission Protocol    -   SDAP Service Data Adaptation Protocol, Service Data Adaptation        Protocol layer    -   SDL Supplementary Downlink    -   SDNF Structured Data Storage Network Function    -   SDP Service Discovery Protocol (Bluetooth related)    -   SDSF Structured Data Storage Function    -   SDU Service Data Unit    -   SEAF Security Anchor Function    -   SeNB secondary eNB    -   SEPP Security Edge Protection Pro12    -   SFI Slot format indication    -   SFTD Space frequency Time Diversity, SFN and frame timing        difference    -   SFN System Frame Number    -   SgNB Secondary gNB    -   SGSN Serving GPRS Support Node    -   S-GW Serving Gateway    -   SI System Information    -   SI-RNTI System Information RNTI    -   SIB System Information Block    -   SIM Subscriber Identity Module    -   SIP Session Initiated Protocol    -   SiP System in Package    -   SL Sidelink    -   SLA Service Level Agreement    -   SM Session Management    -   SMF Session Management Function    -   SMS Short Message Service    -   SMSF SMS Function    -   SMTC SSB-based Measurement Timing Configuration    -   SN Secondary Node, Sequence Number    -   SoC System on Chip    -   SON Self-Organizing Network    -   SpCell Special Cell    -   SP-CSI-RNTI Semi-Persistent CSI RNTI    -   SPS Semi-Persistent Scheduling    -   SQN Sequence number    -   SR Scheduling Request    -   SRB Signalling Radio Bearer    -   SRS Sounding Reference Signal    -   SS Synchronization Signal    -   SSB Synchronization Signal Block, SS/PBCH Block    -   SSBRI SS/PBCH Block Resource Indicator, Synchronization Signal        Block Resource Indicator    -   SSC Session and Service Continuity    -   SS-RSRP Synchronization Signal based Reference Signal Received        Power    -   SS-RSRQ Synchronization Signal based Reference Signal Received        Quality    -   SS-SINR Synchronization Signal based Signal to Noise and        Interference Ratio    -   SSS Secondary Synchronization Signal    -   SSSG Search Space Set Group    -   SSSIF Search Space Set Indicator    -   SST Slice/Service Types    -   SU-MIMO Single User MIMO    -   SUL Supplementary Uplink    -   TA Timing Advance, Tracking Area    -   TAC Tracking Area Code    -   TAG Timing Advance Group    -   TAU Tracking Area Update    -   TB Transport Block    -   TBS Transport Block Size    -   TBD To Be Defined    -   TCI Transmission Configuration Indicator    -   TCP Transmission Communication Protocol    -   TDD Time Division Duplex    -   TDM Time Division Multiplexing    -   TDMA Time Division Multiple Access    -   TE Terminal Equipment    -   TEID Tunnel End Point Identifier    -   TFT Traffic Flow Template    -   TMSI Temporary Mobile Subscriber Identity    -   TNL Transport Network Layer    -   TPC Transmit Power Control    -   TPMI Transmitted Precoding Matrix Indicator    -   TR Technical Report    -   TRP, TRxP Transmission Reception Point    -   TRS Tracking Reference Signal    -   TRx Transceiver    -   TS Technical Specifications, Technical Standard    -   TTI Transmission Time Interval    -   Tx Transmission, Transmitting, Transmitter    -   U-RNTI UTRAN Radio Network Temporary Identity    -   UART Universal Asynchronous Receiver and Transmitter    -   UCI Uplink Control Information    -   UE User Equipment    -   UDM Unified Data Management    -   UDP User Datagram Protocol    -   UDSF Unstructured Data Storage Network Function    -   UICC Universal Integrated Circuit Card    -   UL Uplink    -   UM Unacknowledged Mode    -   UML Unified Modelling Language    -   UMTS Universal Mobile Telecommunications System    -   UP User Plane    -   UPF User Plane Function    -   URI Uniform Resource Identifier    -   URL Uniform Resource Locator    -   URLLC Ultra-Reliable and Low Latency    -   USB Universal Serial Bus    -   USIM Universal Subscriber Identity Module    -   USS UE-specific search space    -   UTRA UMTS Terrestrial Radio Access    -   UTRAN Universal Terrestrial Radio Access Network    -   UwPTS Uplink Pilot Time Slot    -   V2I Vehicle-to-Infrastruction    -   V2P Vehicle-to-Pedestrian    -   V2V Vehicle-to-Vehicle    -   V2X Vehicle-to-everything    -   VIM Virtualized Infrastructure Manager    -   VL Virtual Link,    -   VLAN Virtual LAN, Virtual Local Area Network    -   VM Virtual Machine    -   VNF Virtualized Network Function    -   VNFFG VNF Forwarding Graph    -   VNFFGD VNF Forwarding Graph Descriptor    -   VNFM VNF Manager    -   VoIP Voice-over-IP, Voice-over-Internet Protocol    -   VPLMN Visited Public Land Mobile Network    -   VPN Virtual Private Network    -   VRB Virtual Resource Block    -   WiMAX Worldwide Interoperability for Microwave Access    -   WLAN Wireless Local Area Network    -   WMAN Wireless Metropolitan Area Network    -   WPAN Wireless Personal Area Network    -   X2-C X2-Control plane    -   X2-U X2-User plane    -   XML eXtensible Markup Language    -   XRES EXpected user RESponse    -   XOR eXclusive OR    -   ZC Zadoff-Chu    -   ZP Zero Power

Terminology

For the purposes of the present document, the following terms anddefinitions are applicable to the examples and embodiments discussedherein.

The term “circuitry” as used herein refers to, is part of, or includeshardware components such as an electronic circuit, a logic circuit, aprocessor (shared, dedicated, or group) and/or memory (shared,dedicated, or group), an Application Specific Integrated Circuit (ASIC),a field-programmable device (FPD) (e.g., a field-programmable gate array(FPGA), a programmable logic device (PLD), a complex PLD (CPLD), ahigh-capacity PLD (HCPLD), a structured ASIC, or a programmable SoC),digital signal processors (DSPs), etc., that are configured to providethe described functionality. In some embodiments, the circuitry mayexecute one or more software or firmware programs to provide at leastsome of the described functionality. The term “circuitry” may also referto a combination of one or more hardware elements (or a combination ofcircuits used in an electrical or electronic system) with the programcode used to carry out the functionality of that program code. In theseembodiments, the combination of hardware elements and program code maybe referred to as a particular type of circuitry.

The term “processor circuitry” as used herein refers to, is part of, orincludes circuitry capable of sequentially and automatically carryingout a sequence of arithmetic or logical operations, or recording,storing, and/or transferring digital data. The term “processorcircuitry” may refer to one or more application processors, one or morebaseband processors, a physical central processing unit (CPU), asingle-core processor, a dual-core processor, a triple-core processor, aquad-core processor, and/or any other device capable of executing orotherwise operating computer-executable instructions, such as programcode, software modules, and/or functional processes. The terms“application circuitry” and/or “baseband circuitry” may be consideredsynonymous to, and may be referred to as, “processor circuitry.”

The term “interface circuitry” as used herein refers to, is part of, orincludes circuitry that enables the exchange of information between twoor more components or devices. The term “interface circuitry” may referto one or more hardware interfaces, for example, buses, I/O interfaces,peripheral component interfaces, network interface cards, and/or thelike.

The term “user equipment” or “UE” as used herein refers to a device withradio communication capabilities and may describe a remote user ofnetwork resources in a communications network. The term “user equipment”or “UE” may be considered synonymous to, and may be referred to as,client, mobile, mobile device, mobile terminal, user terminal, mobileunit, mobile station, mobile user, subscriber, user, remote station,access agent, user agent, receiver, radio equipment, reconfigurableradio equipment, reconfigurable mobile device, etc. Furthermore, theterm “user equipment” or “UE” may include any type of wireless/wireddevice or any computing device including a wireless communicationsinterface.

The term “network element” as used herein refers to physical orvirtualized equipment and/or infrastructure used to provide wired orwireless communication network services. The term “network element” maybe considered synonymous to and/or referred to as a networked computer,networking hardware, network equipment, network node, router, switch,hub, bridge, radio network controller, RAN device, RAN node, gateway,server, virtualized VNF, NFVI, and/or the like.

The term “computer system” as used herein refers to any typeinterconnected electronic devices, computer devices, or componentsthereof. Additionally, the term “computer system” and/or “system” mayrefer to various components of a computer that are communicativelycoupled with one another. Furthermore, the term “computer system” and/or“system” may refer to multiple computer devices and/or multiplecomputing systems that are communicatively coupled with one another andconfigured to share computing and/or networking resources.

The term “appliance,” “computer appliance,” or the like, as used hereinrefers to a computer device or computer system with program code (e.g.,software or firmware) that is specifically designed to provide aspecific computing resource. A “virtual appliance” is a virtual machineimage to be implemented by a hypervisor-equipped device that virtualizesor emulates a computer appliance or otherwise is dedicated to provide aspecific computing resource.

The term “resource” as used herein refers to a physical or virtualdevice, a physical or virtual component within a computing environment,and/or a physical or virtual component within a particular device, suchas computer devices, mechanical devices, memory space, processor/CPUtime, processor/CPU usage, processor and accelerator loads, hardwaretime or usage, electrical power, input/output operations, ports ornetwork sockets, channel/link allocation, throughput, memory usage,storage, network, database and applications, workload units, and/or thelike. A “hardware resource” may refer to compute, storage, and/ornetwork resources provided by physical hardware element(s). A“virtualized resource” may refer to compute, storage, and/or networkresources provided by virtualization infrastructure to an application,device, system, etc. The term “network resource” or “communicationresource” may refer to resources that are accessible by computerdevices/systems via a communications network. The term “systemresources” may refer to any kind of shared entities to provide services,and may include computing and/or network resources. System resources maybe considered as a set of coherent functions, network data objects orservices, accessible through a server where such system resources resideon a single host or multiple hosts and are clearly identifiable.

The term “channel” as used herein refers to any transmission medium,either tangible or intangible, which is used to communicate data or adata stream. The term “channel” may be synonymous with and/or equivalentto “communications channel,” “data communications channel,”“transmission channel,” “data transmission channel,” “access channel,”“data access channel,” “link,” “data link,” “carrier,” “radiofrequencycarrier,” and/or any other like term denoting a pathway or mediumthrough which data is communicated. Additionally, the term “link” asused herein refers to a connection between two devices through a RAT forthe purpose of transmitting and receiving information.

The terms “instantiate,” “instantiation,” and the like as used hereinrefers to the creation of an instance. An “instance” also refers to aconcrete occurrence of an object, which may occur, for example, duringexecution of program code.

The terms “coupled,” “communicatively coupled,” along with derivativesthereof are used herein. The term “coupled” may mean two or moreelements are in direct physical or electrical contact with one another,may mean that two or more elements indirectly contact each other butstill cooperate or interact with each other, and/or may mean that one ormore other elements are coupled or connected between the elements thatare said to be coupled with each other. The term “directly coupled” maymean that two or more elements are in direct contact with one another.The term “communicatively coupled” may mean that two or more elementsmay be in contact with one another by a means of communication includingthrough a wire or other interconnect connection, through a wirelesscommunication channel or ink, and/or the like.

The term “information element” refers to a structural element containingone or more fields. The term “field” refers to individual contents of aninformation element, or a data element that contains content.

The term “SMTC” refers to an SSB-based measurement timing configurationconfigured by SSB-MeasurementTimingConfiguration.

The term “SSB” refers to an SS/PBCH block.

The term “a “Primary Cell” refers to the MCG cell, operating on theprimary frequency, in which the UE either performs the initialconnection establishment procedure or initiates the connectionre-establishment procedure.

The term “Primary SCG Cell” refers to the SCG cell in which the UEperforms random access when performing the Reconfiguration with Syncprocedure for DC operation.

The term “Secondary Cell” refers to a cell providing additional radioresources on top of a Special Cell for a UE configured with CA.

The term “Secondary Cell Group” refers to the subset of serving cellscomprising the PSCell and zero or more secondary cells for a UEconfigured with DC.

The term “Serving Cell” refers to the primary cell for a UE inRRC_CONNECTED not configured with CA/DC there is only one serving cellcomprising of the primary cell.

The term “serving cell” or “serving cells” refers to the set of cellscomprising the Special Cell(s) and all secondary cells for a UE inRRC_CONNECTED configured with CA/.

The term “Special Cell” refers to the PCell of the MCG or the PSCell ofthe SCG for DC operation; otherwise, the term “Special Cell” refers tothe Pcell.

What is claimed is:
 1. A user equipment (UE), comprising: at least oneprocessor configured to: construct a precoding matrix based on a linearcombination of a plurality of mutually orthogonal digital Fouriertransformation (DFT) spatial beams; determine a number of bits for aprecoding matrix indicator (PMI) of the precoding matrix; determine aspace frequency matrix based, at least in part, on the number of bitsfor the PMI and the precoding matrix; compress the space frequencymatrix; and determine a compressed PMI based, at least in part, on thespace frequency matrix; and radio front end circuitry configured totransmit the compressed PMI over a wireless network to a base station(BS).
 2. The UE of claim 1, wherein the compressing the space frequencymatrix includes using linear transformation.
 3. The UE of claim 1,wherein the compressing the space frequency matrix includes usingfrequency domain compression, wherein the frequency domain compressioncomprises multiplying the space frequency matrix with a complex number,the complex number having an arbitrary phase and unit amplitude.
 4. TheUE of claim 1, wherein the compressing the space frequency matrixincludes using time domain compression, wherein the time domaincompression comprises deriving a first set of time domain coefficientsfrom a second set of time domain coefficients.
 5. The UE of claim 1,wherein the radio front end circuitry includes a radio frequencyintegrated circuit (RFIC) configured to transmit the compressed PMI. 6.The UE of claim 1, wherein the at least one processor is furtherconfigured to generate a channel state information (CSI) report, whereinthe CSI report includes a channel quality indicator (CQI), a rankindicator (RI), and the PMI, and wherein the CSI report comprises afirst part and a second part, the first part having a fixed payloadsize.
 7. The UE of claim 6, wherein a payload size of the second partdepends on content of the first part.
 8. A method of operating a userequipment (UE), comprising: constructing a precoding matrix based on alinear combination of a plurality of mutually orthogonal digital Fouriertransformation (DFT) spatial beams; determining a number of bits for aprecoding matrix indicator (PMI) of the precoding matrix; determining aspace frequency matrix based, at least in part, on the number of bitsfor the PMI and the precoding matrix; compressing the space frequencymatrix; determining a compressed PMI based, at least in part, on thespace frequency matrix; and transmitting the compressed PMI over awireless network to a base station (BS).
 9. The method of claim 8,wherein the compressing the space frequency matrix includes using lineartransformation.
 10. The method of claim 8, wherein the compressing thespace frequency matrix includes using frequency domain compression,wherein the frequency domain compression comprises multiplying the spacefrequency matrix with a complex number, the complex number having anarbitrary phase and unit amplitude.
 11. The method of claim 8, whereinthe compressing the space frequency matrix includes using time domaincompression, wherein the time domain compression comprises deriving afirst set of time domain coefficients from a second set of time domaincoefficients.
 12. The method of claim 8, wherein the UE includes radiofront end circuitry that includes a radio frequency integrated circuit(RFIC) configured to transmit the compressed PMI.
 13. The method ofclaim 8, wherein the UE includes at least one processor that isconfigured to generate a channel state information (CSI) report, whereinthe CSI report includes a channel quality indicator (CQI), a rankindicator (RI), and the PMI, and wherein the CSI report comprises afirst part and a second part, the first part having a fixed payloadsize.
 14. The method of claim 13, wherein a payload size of the secondpart depends on content of the first part.
 15. Non-transitorycomputer-readable media (CRM) comprising computer instructions, whereupon execution of the computer instructions by one or more processors,causes the one or more processors to: construct a precoding matrix basedon a linear combination of a plurality of mutually orthogonal digitalFourier transformation (DFT) spatial beams; determine a number of bitsfor a precoding matrix indicator (PMI) of the precoding matrix;determine a space frequency matrix based, at least in part, on thenumber of bits for the PMI and the precoding matrix; compress the spacefrequency matrix; determine a compressed PMI based, at least in part, onthe space frequency matrix; and cause to transmit the compressed PMIover a wireless network to a base station (BS).
 16. The non-transitoryCRM of claim 15, wherein the computer instructions further cause the oneor more processors to compress the space frequency matrix that includesusing linear transformation.
 17. The non-transitory CRM of claim 15,wherein the computer instructions further cause the one or moreprocessors to compress the space frequency matrix that includes usingfrequency domain compression, wherein the frequency domain compressioncomprises multiplying the space frequency matrix with a complex number,the complex number having an arbitrary phase and unit amplitude.
 18. Thenon-transitory CRM of claim 15, wherein the computer instructionsfurther cause the one or more processors to compress the space frequencymatrix that includes using time domain compression, wherein the timedomain compression comprises deriving a first set of time domaincoefficients from a second set of time domain coefficients.
 19. Thenon-transitory CRM of claim 15, wherein the one or more processors arefurther configured to generate a channel state information (CSI) report,wherein the CSI report includes a channel quality indicator (CQI), arank indicator (RI), and the PMI, and wherein the CSI report comprises afirst part and a second part, the first part having a fixed payloadsize.
 20. The non-transitory CRM of claim 19, wherein a payload size ofthe second part depends on content of the first part.